Rakefile is cleaned

Rakefile

@@ -10,19 +10,5 @@ Rake::TestTask.new(:test) do |test|
   test.libs << 'test'
   test.pattern = 'test/*_test.rb'
   test.verbose = true
-  # Ruby built-in warnings contain way too much noise to be useful. Consider turning them on again when the following issues are accepted in ruby:
-  # * https://bugs.ruby-lang.org/issues/10967 (remove warning: private attribute?)
-  # * https://bugs.ruby-lang.org/issues/12299 (customized warning handling)
   test.warning = false
 end
-
-# Rake::TestTask.new(:rails) do |test|
-#   test.libs << 'test/rails'
-#   test.test_files = FileList['test/rails4.2/*_test.rb']
-#   test.verbose = true
-# end
-
-# rails_task = Rake::Task["rails"]
-# test_task = Rake::Task["test"]
-# default_task.enhance { test_task.invoke }
-# default_task.enhance { rails_task.invoke }