add data_migration for rename field for attribute_field. not yet tested

lib/tasks/data_migration.rake

@@ -96,4 +96,8 @@ namespace :data_migration do
     app.save!
   end
 
+  task :rename_attribute_field => :environment do
+     AttributeField.collection.update({},{'$rename' => {'title' => 'locale_title'}}, multi: true, safe: true) 
+  end
+
 end