Poll task status until STOPPED

def _track_tasks(task_ids, cluster):
    """Poll task status until STOPPED"""
    while True:
        statuses = _get_task_statuses(task_ids, cluster)
        if all([status == 'STOPPED' for status in statuses]):
            logger.info('ECS tasks {0} STOPPED'.format(','.join(task_ids)))
            break
        time.sleep(POLL_TIME)
        logger.debug('ECS task status for tasks {0}: {1}'.format(task_ids, statuses))