docker-custodian crashing when cleaning up.

[Hasan Niz]

Getting the error when running docker-custodian:

Traceback (most recent call last):
  File "/usr/bin/dcgc", line 5, in <module>
    from pkg_resources import load_entry_point
  File "/usr/lib/python2.7/site-packages/pkg_resources.py", line 2797, in <module>
    parse_requirements(__requires__), Environment()
  File "/usr/lib/python2.7/site-packages/pkg_resources.py", line 576, in resolve
    raise DistributionNotFound(req)
pkg_resources.DistributionNotFound: backports.ssl-match-hostname>=3.5

[Kyle Cascade]

Dupe of #37