Fixes according to review

composer.json

@@ -14,7 +14,7 @@
         }
     ],
     "require": {
-        "php": ">=7.2",
+        "php": "^7.2 || ^8.0",
         "symfony/polyfill-ctype": "^1.8"
     },
     "conflict": {

tests/AssertTest.php

@@ -16,6 +16,7 @@
 use Error;
 use Exception;
 use LogicException;
+use PHPUnit\Framework\TestCase;
 use RuntimeException;
 use stdClass;
 use Webmozart\Assert\Assert;
@@ -25,7 +26,7 @@
  *
  * @author Bernhard Schussek <[email protected]>
  */
-class AssertTest extends BaseTestCase
+class AssertTest extends TestCase
 {
     private static $resource;
 
@@ -422,7 +423,7 @@ public function getTests()
             // no tests for readable()/writable() for now
             array('classExists', array(__CLASS__), true),
             array('classExists', array(__NAMESPACE__.'\Foobar'), false),
-            array('subclassOf', array(__CLASS__, 'Webmozart\Assert\Tests\BaseTestCase'), true),
+            array('subclassOf', array(__CLASS__, 'PHPUnit\Framework\TestCase'), true),
             array('subclassOf', array(__CLASS__, 'stdClass'), false),
             array('interfaceExists', array('\Countable'), true),
             array('interfaceExists', array(__CLASS__), false),