fix user devise serializer to show cover updated_at

app/serializers/user_devise_serializer.rb

@@ -11,5 +11,5 @@ class UserDeviseSerializer < ActiveModel::Serializer
 
   attributes :id, :email, :provider, :avatar_file_name, :avatar_content_type, :uid, :name, :avatar_file_size, :avatar_updated_at,
              :bookmarks_count, :user_category_id, :score, :follows_count, :deleted_at, :description, :likes_count,
-             :learning_objects_count, :collections_count, :cover_file_name, :cover_content_type, :cover_file_size
+             :learning_objects_count, :collections_count, :cover_file_name, :cover_content_type, :cover_file_size, :cover_updated_at
 end