CI against Ruby 3.0

.travis.yml

@@ -9,6 +9,7 @@ rvm:
   - "2.5.7"
   - "2.6.5"
   - "2.7.0"
+  - "3.0.0"
 gemfile:
   - gemfiles/rails_5.0.gemfile
   - gemfiles/rails_5.1.gemfile
@@ -19,5 +20,11 @@ matrix:
   exclude:
     - rvm: 2.4.9
       gemfile: gemfiles/rails_6.0.gemfile
+    - rvm: 3.0.0
+      gemfile: gemfiles/rails_5.0.gemfile
+    - rvm: 3.0.0
+      gemfile: gemfiles/rails_5.1.gemfile
+    - rvm: 3.0.0
+      gemfile: gemfiles/rails_5.2.gemfile
 
 script: "bundle exec rake spec"

gemfiles/rails_5.0.gemfile

@@ -15,10 +15,4 @@ platform :ruby do
   gem 'sqlite3', '~> 1.3.0'
 end
 
-platforms :rbx do
-  gem 'racc'
-  gem 'rubysl', '~> 2.0'
-  gem 'psych'
-end
-
 gemspec :path => '../'

gemfiles/rails_5.1.gemfile

@@ -15,10 +15,4 @@ platform :ruby do
   gem 'sqlite3', '~> 1.3.0'
 end
 
-platforms :rbx do
-  gem 'racc'
-  gem 'rubysl', '~> 2.0'
-  gem 'psych'
-end
-
 gemspec :path => '../'

gemfiles/rails_5.2.gemfile

@@ -15,10 +15,4 @@ platform :ruby do
   gem 'sqlite3', '~> 1.3.0'
 end
 
-platforms :rbx do
-  gem 'racc'
-  gem 'rubysl', '~> 2.0'
-  gem 'psych'
-end
-
 gemspec :path => '../'

gemfiles/rails_6.0.gemfile

@@ -15,10 +15,4 @@ platform :ruby do
   gem 'sqlite3'
 end
 
-platforms :rbx do
-  gem 'racc'
-  gem 'rubysl', '~> 2.0'
-  gem 'psych'
-end
-
 gemspec :path => '../'

spec/associations/active_record_extensions_spec.rb

@@ -180,7 +180,7 @@ class Book < ActiveRecord::Base
         it "doesn't raise any exception when the belongs_to association class can't be autoloaded" do
           # Simulate autoloader
           allow_any_instance_of(String).to receive(:constantize).and_raise(LoadError, "Unable to autoload constant NonExistent")
-          expect { School.belongs_to :city, {class_name: 'NonExistent'} }.not_to raise_error
+          expect { School.belongs_to :city, class_name: 'NonExistent' }.not_to raise_error
         end
       end