Allow Rails 6 and test with all versions

.travis.yml

@@ -6,13 +6,19 @@ rvm:
  - 2.1
  - 2.2.5
  - 2.3.1
+ - 2.4.5
+ - 2.5.4
+ - 2.6.3
  - rbx-2
 
 gemfile:
   - gemfiles/Gemfile-rails-4-0
   - gemfiles/Gemfile-rails-4-1
   - gemfiles/Gemfile-rails-4-2
   - gemfiles/Gemfile-rails-5-0
+  - gemfiles/Gemfile-rails-5-1
+  - gemfiles/Gemfile-rails-5-2
+  - gemfiles/Gemfile-rails-6-0
   - gemfiles/Gemfile-sprockets-2-11
   - gemfiles/Gemfile-sprockets-2-12
   - gemfiles/Gemfile-sprockets-2-8

Gemfile

@@ -4,4 +4,3 @@ source "https://rubygems.org"
 gemspec
 
 gem "rails", github: "rails/rails"
-gem "arel", github: "rails/arel"

gemfiles/Gemfile-rails-5-1

@@ -0,0 +1,7 @@
+source "https://rubygems.org"
+
+# Specify your gem"s dependencies in sass-rails.gemspec
+gemspec path: ".."
+
+gem "rails", github: 'rails/rails', branch: '5-1-stable'
+gem 'mime-types', '< 3', require: false if RUBY_VERSION.start_with?('1.9')

gemfiles/Gemfile-rails-5-2

@@ -0,0 +1,7 @@
+source "https://rubygems.org"
+
+# Specify your gem"s dependencies in sass-rails.gemspec
+gemspec path: ".."
+
+gem "rails", github: 'rails/rails', branch: '5-2-stable'
+gem 'mime-types', '< 3', require: false if RUBY_VERSION.start_with?('1.9')

gemfiles/Gemfile-rails-6-0

@@ -0,0 +1,6 @@
+source "https://rubygems.org"
+
+# Specify your gem"s dependencies in sass-rails.gemspec
+gemspec path: ".."
+
+gem "rails", github: 'rails/rails', branch: '6-0-stable'

sass-rails.gemspec

@@ -13,7 +13,7 @@ Gem::Specification.new do |s|
   s.description = %q{Sass adapter for the Rails asset pipeline.}
   s.license     = %q{MIT}
 
-  s.add_dependency 'railties',        '>= 4.0.0', '< 6'
+  s.add_dependency 'railties',        '>= 4.0.0'
   s.add_dependency 'sass',            '~> 3.1'
   s.add_dependency 'sprockets-rails', '>= 2.0', '< 4.0'
   s.add_dependency 'sprockets',       '>= 2.8', '< 4.0'