diff --git a/.github/workflows/coding-standards.yml b/.github/workflows/coding-standards.yml
index 2c23bd4..cd666ae 100644
--- a/.github/workflows/coding-standards.yml
+++ b/.github/workflows/coding-standards.yml
@@ -14,7 +14,7 @@ env:
 jobs:
   coding-standards:
     name: "CS Fixer & PHPStan"
-    runs-on: "ubuntu-18.04"
+    runs-on: "ubuntu-20.04"
 
     strategy:
       matrix:
diff --git a/.github/workflows/continuous-integration.yml b/.github/workflows/continuous-integration.yml
index 42b2d41..1424248 100644
--- a/.github/workflows/continuous-integration.yml
+++ b/.github/workflows/continuous-integration.yml
@@ -14,7 +14,7 @@ env:
 jobs:
   phpunit:
     name: "PHPUnit (PHP ${{ matrix.php }})"
-    runs-on: "ubuntu-18.04"
+    runs-on: "ubuntu-20.04"
 
     strategy:
       matrix:
@@ -25,6 +25,7 @@ jobs:
           - "7.2"
           - "7.3"
           - "7.4"
+          - "8.0"
 
     steps:
       - name: "Checkout"
@@ -65,7 +66,7 @@ jobs:
 
   phpunit-coverage:
     name: "PHPUnit coverage (PHP ${{ matrix.php }})"
-    runs-on: "ubuntu-18.04"
+    runs-on: "ubuntu-20.04"
 
     strategy:
       matrix:
@@ -118,7 +119,7 @@ jobs:
 
   phpunit-lowest:
     name: "PHPUnit lowest deps (PHP ${{ matrix.php }})"
-    runs-on: "ubuntu-18.04"
+    runs-on: "ubuntu-20.04"
 
     strategy:
       matrix:
@@ -161,7 +162,7 @@ jobs:
 
   phpunit-composerv2:
     name: "PHPUnit with Composer v2 (PHP ${{ matrix.php }})"
-    runs-on: "ubuntu-18.04"
+    runs-on: "ubuntu-20.04"
 
     strategy:
       matrix:
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 2ed6a99..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,34 +0,0 @@
-dist: xenial
-os: linux
-language: php
-
-# avoid double Travis build when the PR is created on upstream
-if: |
-    type = pull_request OR \
-    branch = master
-
-jobs:
-    include:
-        - php: 8.0
-          env: SYMFONY_PHPUNIT_VERSION=7.5
-    fast_finish: true
-    allow_failures:
-        - php: 8.0
-
-cache:
-    directories:
-        - $HOME/.composer/cache/files
-
-before_install:
-    - if [ -n "$GH_TOKEN" ]; then composer config github-oauth.github.com ${GH_TOKEN}; fi;
-
-install:
-    - if [ "$CS_FIXER" != "run" ]; then composer remove friendsofphp/php-cs-fixer --dev --no-progress --no-update ; fi;
-    - composer update --prefer-dist --no-progress -o
-    - php vendor/bin/simple-phpunit install
-
-before_script:
-    - mkdir -p build/logs
-
-script:
-    - php vendor/bin/simple-phpunit -v
diff --git a/README.md b/README.md
index a1eebee..e3f3cf7 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,6 @@
 # Readability
 
 ![CI](https://github.com/j0k3r/php-readability/workflows/CI/badge.svg)
-[![Build Status](https://travis-ci.org/j0k3r/php-readability.svg?branch=master)](https://travis-ci.org/j0k3r/php-readability)
 [![Coverage Status](https://coveralls.io/repos/j0k3r/php-readability/badge.svg?branch=master&service=github)](https://coveralls.io/github/j0k3r/php-readability/?branch=master)
 [![Total Downloads](https://poser.pugx.org/j0k3r/php-readability/downloads)](https://packagist.org/packages/j0k3r/php-readability)
 [![License](https://poser.pugx.org/j0k3r/php-readability/license)](https://packagist.org/packages/j0k3r/php-readability)
diff --git a/src/Readability.php b/src/Readability.php
index 1ed93ea..db2e27a 100644
--- a/src/Readability.php
+++ b/src/Readability.php
@@ -187,6 +187,9 @@ public function __construct($html, $url = null, $parser = 'libxml', $use_tidy =
         $this->loadHtml();
     }
 
+    /**
+     * @return void
+     */
     public function setLogger(LoggerInterface $logger)
     {
         $this->logger = $logger;
diff --git a/tests/ReadabilityTest.php b/tests/ReadabilityTest.php
index e345947..dfe3cf6 100644
--- a/tests/ReadabilityTest.php
+++ b/tests/ReadabilityTest.php
@@ -74,7 +74,7 @@ public function testInitNoContent()
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
         $this->assertEmpty($readability->getTitle()->getInnerHtml());
-        $this->assertContains('Sorry, Readability was unable to parse this page for content.', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('Sorry, Readability was unable to parse this page for content.', $readability->getContent()->getInnerHtml());
     }
 
     public function testInitP()
@@ -85,9 +85,9 @@ public function testInitP()
         $this->assertTrue($res);
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
-        $this->assertContains('<div readability=', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('<div readability=', $readability->getContent()->getInnerHtml());
         $this->assertEmpty($readability->getTitle()->getInnerHtml());
-        $this->assertContains('This is the awesome content :)', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This is the awesome content :)', $readability->getContent()->getInnerHtml());
     }
 
     public function testInitDivP()
@@ -98,9 +98,9 @@ public function testInitDivP()
         $this->assertTrue($res);
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
-        $this->assertContains('<div readability=', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('<div readability=', $readability->getContent()->getInnerHtml());
         $this->assertEmpty($readability->getTitle()->getInnerHtml());
-        $this->assertContains('This is the awesome content :)', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This is the awesome content :)', $readability->getContent()->getInnerHtml());
     }
 
     public function testInitDiv()
@@ -112,9 +112,9 @@ public function testInitDiv()
         $this->assertTrue($res);
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
-        $this->assertContains('<div readability=', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('<div readability=', $readability->getContent()->getInnerHtml());
         $this->assertEmpty($readability->getTitle()->getInnerHtml());
-        $this->assertContains('This is the awesome content :)', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This is the awesome content :)', $readability->getContent()->getInnerHtml());
     }
 
     public function testWithFootnotes()
@@ -127,11 +127,11 @@ public function testWithFootnotes()
         $this->assertTrue($res);
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
-        $this->assertContains('<div readability=', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('<div readability=', $readability->getContent()->getInnerHtml());
         $this->assertEmpty($readability->getTitle()->getInnerHtml());
-        $this->assertContains('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
-        $this->assertContains('readabilityFootnoteLink', $readability->getContent()->getInnerHtml());
-        $this->assertContains('readabilityLink-3', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('readabilityFootnoteLink', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('readabilityLink-3', $readability->getContent()->getInnerHtml());
     }
 
     public function testStandardClean()
@@ -144,11 +144,11 @@ public function testStandardClean()
         $this->assertTrue($res);
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
-        $this->assertContains('<div readability=', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('<div readability=', $readability->getContent()->getInnerHtml());
         $this->assertEmpty($readability->getTitle()->getInnerHtml());
-        $this->assertContains('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
-        $this->assertContains('will NOT be removed', $readability->getContent()->getInnerHtml());
-        $this->assertNotContains('<h2>', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('will NOT be removed', $readability->getContent()->getInnerHtml());
+        $this->assertStringNotContainsString('<h2>', $readability->getContent()->getInnerHtml());
     }
 
     public function testWithIframe()
@@ -160,10 +160,10 @@ public function testWithIframe()
         $this->assertTrue($res);
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
-        $this->assertContains('<div readability=', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('<div readability=', $readability->getContent()->getInnerHtml());
         $this->assertEmpty($readability->getTitle()->getInnerHtml());
-        $this->assertContains('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
-        $this->assertContains('nofollow', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('nofollow', $readability->getContent()->getInnerHtml());
     }
 
     public function testWithArticle()
@@ -175,10 +175,10 @@ public function testWithArticle()
         $this->assertTrue($res);
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
-        $this->assertContains('alt="article"', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('alt="article"', $readability->getContent()->getInnerHtml());
         $this->assertEmpty($readability->getTitle()->getInnerHtml());
-        $this->assertContains('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
-        $this->assertContains('nofollow', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('nofollow', $readability->getContent()->getInnerHtml());
     }
 
     public function testWithAside()
@@ -191,9 +191,9 @@ public function testWithAside()
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
         $this->assertEmpty($readability->getTitle()->getInnerHtml());
-        $this->assertContains('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
-        $this->assertNotContains('<aside>', $readability->getContent()->getInnerHtml());
-        $this->assertContains('<footer readability="5"/>', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
+        $this->assertStringNotContainsString('<aside>', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('<footer readability="5"/>', $readability->getContent()->getInnerHtml());
     }
 
     public function testWithClasses()
@@ -205,10 +205,10 @@ public function testWithClasses()
         $this->assertTrue($res);
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
-        $this->assertContains('alt="article"', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('alt="article"', $readability->getContent()->getInnerHtml());
         $this->assertEmpty($readability->getTitle()->getInnerHtml());
-        $this->assertContains('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
-        $this->assertNotContains('This text should be removed', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
+        $this->assertStringNotContainsString('This text should be removed', $readability->getContent()->getInnerHtml());
     }
 
     public function testWithClassesWithoutLightClean()
@@ -221,10 +221,10 @@ public function testWithClassesWithoutLightClean()
         $this->assertTrue($res);
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
-        $this->assertContains('alt="article"', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('alt="article"', $readability->getContent()->getInnerHtml());
         $this->assertEmpty($readability->getTitle()->getInnerHtml());
-        $this->assertContains('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
-        $this->assertNotContains('This text should be removed', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
+        $this->assertStringNotContainsString('This text should be removed', $readability->getContent()->getInnerHtml());
     }
 
     public function testWithTd()
@@ -237,7 +237,7 @@ public function testWithTd()
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
         $this->assertEmpty($readability->getTitle()->getInnerHtml());
-        $this->assertContains('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
     }
 
     public function testWithSameClasses()
@@ -250,8 +250,8 @@ public function testWithSameClasses()
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
         $this->assertEmpty($readability->getTitle()->getInnerHtml());
-        $this->assertContains('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
-        $this->assertContains('This text is also an awesome text and you should know that', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This text is also an awesome text and you should know that', $readability->getContent()->getInnerHtml());
     }
 
     public function testWithScript()
@@ -264,8 +264,8 @@ public function testWithScript()
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
         $this->assertEmpty($readability->getTitle()->getInnerHtml());
-        $this->assertContains('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
-        $this->assertNotContains('This text is also an awesome text and you should know that', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
+        $this->assertStringNotContainsString('This text is also an awesome text and you should know that', $readability->getContent()->getInnerHtml());
     }
 
     public function testTitle()
@@ -278,8 +278,8 @@ public function testTitle()
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
         $this->assertEquals('this is my title', $readability->getTitle()->getInnerHtml());
-        $this->assertContains('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
-        $this->assertNotContains('This text is also an awesome text and you should know that', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
+        $this->assertStringNotContainsString('This text is also an awesome text and you should know that', $readability->getContent()->getInnerHtml());
     }
 
     public function testTitleWithDash()
@@ -292,8 +292,8 @@ public function testTitleWithDash()
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
         $this->assertEquals('title2 - title3', $readability->getTitle()->getInnerHtml());
-        $this->assertContains('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
-        $this->assertNotContains('This text is also an awesome text and you should know that', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
+        $this->assertStringNotContainsString('This text is also an awesome text and you should know that', $readability->getContent()->getInnerHtml());
     }
 
     public function testTitleWithDoubleDot()
@@ -306,8 +306,8 @@ public function testTitleWithDoubleDot()
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
         $this->assertEquals('title2 : title3', $readability->getTitle()->getInnerHtml());
-        $this->assertContains('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
-        $this->assertNotContains('This text is also an awesome text and you should know that', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
+        $this->assertStringNotContainsString('This text is also an awesome text and you should know that', $readability->getContent()->getInnerHtml());
     }
 
     public function testTitleTooShortUseH1()
@@ -320,8 +320,8 @@ public function testTitleTooShortUseH1()
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
         $this->assertEquals('this is my h1 title !', $readability->getTitle()->getInnerHtml());
-        $this->assertContains('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
-        $this->assertNotContains('This text is also an awesome text and you should know that', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This is an awesome text with some links, here there are', $readability->getContent()->getInnerHtml());
+        $this->assertStringNotContainsString('This text is also an awesome text and you should know that', $readability->getContent()->getInnerHtml());
     }
 
     // dummy function to be used to the next test
@@ -369,8 +369,8 @@ public function testAutoClosingIframeNotThrowingException()
         $this->assertTrue($res);
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getContent());
         $this->assertInstanceOf('Readability\JSLikeHTMLElement', $readability->getTitle());
-        $this->assertContains('<iframe src="https://www.youtube.com/embed/PUep6xNeKjA" width="560" height="315" frameborder="0" allowfullscreen="allowfullscreen"> </iframe>', $readability->getContent()->getInnerHtml());
-        $this->assertContains('3D Touch', $readability->getTitle()->getInnerHtml());
+        $this->assertStringContainsString('<iframe src="https://www.youtube.com/embed/PUep6xNeKjA" width="560" height="315" frameborder="0" allowfullscreen="allowfullscreen"> </iframe>', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('3D Touch', $readability->getTitle()->getInnerHtml());
     }
 
     /**
@@ -440,7 +440,7 @@ public function testPostFilters()
         $res = $readability->init();
 
         $this->assertTrue($res);
-        $this->assertContains('This  the awesome content :)', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This  the awesome content :)', $readability->getContent()->getInnerHtml());
     }
 
     public function testPreFilters()
@@ -453,7 +453,7 @@ public function testPreFilters()
         $res = $readability->init();
 
         $this->assertTrue($res);
-        $this->assertContains('This the awesome and WONDERFUL content :)', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('This the awesome and WONDERFUL content :)', $readability->getContent()->getInnerHtml());
     }
 
     public function testChildNodeGoneNull()
@@ -479,8 +479,8 @@ public function testKeepFootnotes()
         $res = $readability->init();
 
         $this->assertTrue($res);
-        $this->assertContains('<sup id="fnref1:fnfeed_2"><a href="#fn:fnfeed_2" class="footnote-ref">2</a></sup>', $readability->getContent()->getInnerHtml());
-        $this->assertContains('<a href="#fnref1:fnfeed_2" rev="footnote"', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('<sup id="fnref1:fnfeed_2"><a href="#fn:fnfeed_2" class="footnote-ref">2</a></sup>', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('<a href="#fnref1:fnfeed_2" rev="footnote"', $readability->getContent()->getInnerHtml());
     }
 
     public function testWithWipedBody()
@@ -493,7 +493,7 @@ public function testWithWipedBody()
         $res = $readability->init();
 
         $this->assertTrue($res);
-        $this->assertContains('<a href="alice-I.html">Down the Rabbit-Hole</a>', $readability->getContent()->getInnerHtml());
+        $this->assertStringContainsString('<a href="alice-I.html">Down the Rabbit-Hole</a>', $readability->getContent()->getInnerHtml());
     }
 
     private function getReadability($html, $url = null, $parser = 'libxml', $useTidy = true)