Add support for authenticating via client certificate for Openshift

[kadel]

fixes #533

TODO:

• [ ] add docs
• [x] add tests

[dustymabe]

while the [WIP] text is in the name I assume you guys are still working on this. let me know when you want review.

[kadel]

#dotests

[dustymabe]

Is providing a cert+key in a single file (as mentioned here) a thing? If so are we supporting it with this work?

[dustymabe]

Also, is there any chance we can bundle this bug in as part of this work: https://github.com/projectatomic/atomicapp/issues/529

[dustymabe]

Great job guys.. Sorry about all the comments :( - we are really close though

[cdrage]

@kadel @dustymabe @surajssd

Shout... I forgot to mention that I already implemented this in kubebase.py in my PR...

See https://github.com/projectatomic/atomicapp/pull/712/files

Specifically, kubebase.py functions: _connection() and _certfile()...

[cdrage]

It also includes your issue of base64 encoding (converts files to base64, etc.) as well as cert requests when specifying a certificate.

Originally, i was implementing this for the kubernetes api, but because of how similar both the openshift + kubernetes api http implementations are, the cert passing works for both.

[dustymabe]

@cdrage so you're saying that #533 is handled by #712?

[cdrage]

@dustymabe yes sir

[surajssd]

@dustymabe @cdrage is it time to close this PR?

[concaf]

@cdrage since work around this is being done in #743, let's close this? WDYT?