code: func (s *Scheduler) stackName(appID string) (string, error) {
  	var stackName string
  	err := s.db.QueryRow(`SELECT stack_name FROM stacks WHERE app_id = $1`, appID).Scan(&stackName)
  	if err == sql.ErrNoRows {
  		return "", errNoStack
  	}
  	return stackName, err
  }
docs: // stackName returns the name of the CloudFormation stack for the app id.