Config isn't able to take a string, or StringIO object

[ryphon]

Currently I use Rancher and K8s together. I can currently get my kubeconfig dynamically from a Rancher endpoint.

However, the kubernetes-client doesn't support any capability to use a kubeconfig from string, or even StringIO because a 'split' on the path is required.

The python client should support a kubeconfig via string for situations in which a filesystem either isn't available, or isn't viable.

[ryphon]

I'm working on a pull request now to support a StringIO object, so as to not interfere with the existing 'path' functionality without trying to do some weird detection of a path vs an actual config string.

[roycaihw]

/assign @ryphon