Merge pull request #18763 from robertomiranda/ruby-2.2

Use Module#include instead of send :include, since Module#include is a public method [ci skip]

activerecord/lib/active_record/fixtures.rb

@@ -132,7 +132,7 @@ class FixtureClassNotFound < ActiveRecord::ActiveRecordError #:nodoc:
   #         Digest::SHA2.hexdigest(File.read(Rails.root.join('test/fixtures', path)))
   #       end
   #     end
-  #     ActiveRecord::FixtureSet.context_class.send :include, FixtureFileHelpers
+  #     ActiveRecord::FixtureSet.context_class.include FixtureFileHelpers
   #
   # - use the helper method in a fixture
   #     photo:

guides/source/upgrading_ruby_on_rails.md

@@ -534,7 +534,7 @@ module FixtureFileHelpers
     Digest::SHA2.hexdigest(File.read(Rails.root.join('test/fixtures', path)))
   end
 end
-ActiveRecord::FixtureSet.context_class.send :include, FixtureFileHelpers
+ActiveRecord::FixtureSet.context_class.include FixtureFileHelpers
 ```
 
 ### I18n enforcing available locales