Merge pull request #11220 from aditya-kapoor/add-concern

Change Rails Migration generator module to use AS::Concern

railties/lib/rails/generators/migration.rb

@@ -1,15 +1,14 @@
+require 'active_support/concern'
+
 module Rails
   module Generators
     # Holds common methods for migrations. It assumes that migrations has the
     # [0-9]*_name format and can be used by another frameworks (like Sequel)
     # just by implementing the next migration version method.
     module Migration
+      extend ActiveSupport::Concern
       attr_reader :migration_number, :migration_file_name, :migration_class_name
 
-      def self.included(base) #:nodoc:
-        base.extend ClassMethods
-      end
-
       module ClassMethods
         def migration_lookup_at(dirname) #:nodoc:
           Dir.glob("#{dirname}/[0-9]*_*.rb")