Fail to parse date while container is starting

[kirpichiki]

docker-pretty-ps results with error if container's state like Up 3 seconds (health: starting)

Traceback (most recent call last):
  File "/usr/local/bin/docker-pretty-ps", line 5, in <module>
    dockerprettyps.run_cli()
  File "/usr/local/lib/python2.7/dist-packages/dockerprettyps/__init__.py", line 71, in run_cli
    containers = clean_output(raw_containers)
  File "/usr/local/lib/python2.7/dist-packages/dockerprettyps/__init__.py", line 224, in clean_output
    "created_date": _parse_ps_date(revised_line_split[4].strip()),
  File "/usr/local/lib/python2.7/dist-packages/dockerprettyps/__init__.py", line 285, in _parse_ps_date
    cleaned = cleaned[:cleaned.find(')' + 1)].strip()
TypeError: cannot concatenate 'str' and 'int' objects