[WIP] k8s cmd to api

[cdrage]

This works (and mostly well), although we're blocked a few things:

• Get https://pypi.python.org/pypi/pykube/0.9.0 on CentOS (since we're using that to build)

Other stuff to do:

• Get https://pypi.python.org/pypi/pykube/0.9.0 on other distros too preferably
• Update documentation, since now you can pass --provider-auth to k8s provider
• Make sure all config differences work correctly (having no user, having no auth token in .kube/config, etc.) and error / warn.

To test this PR:
pip install pykube

[dustymabe]

Hey @cdrage, while you do this work if you keep in mind #501 and #421 - @rtnpro made a lot of progress on #421 in #456 so you might take a look at some of the work he did.

[cdrage]

Closing in favour of #712