code: def mark_as_read(self, room_name):
          
          api_meth = self.set_user_items_url(room_name)
          message_ids = self.unread_items(room_name).get('chat')
          if message_ids:
              return self.post(api_meth, data={'chat': message_ids})
          else:
              raise GitterItemsError(room_name)
docs: message_ids return an array
          with unread message ids ['131313231', '323131']