Renamed UserRoles to UserRole Joins, Needed ID column in user_role_joins table

db/migrate/20130423231937_alter_user_roles.rb

@@ -3,7 +3,6 @@ class AlterUserRoles < ActiveRecord::Migration
     rename_table :user_roles, :user_role_joins
     change_table :user_role_joins do |t|
       t.rename :role, :role_id
-      t.remove :id
     end
   end
 end