Support Google Authentication for GKE

[szpotona]

There is a small problem with Google Authentication using the kubernetes package(even with the latest version) that our cloudify kubernetes plugin depends on.

The issue is explained here:
kubernetes-client/python#233

Patching kube_config.py as suggested in the issue thread works and I can use plugin easily and run there simple blueprint from examples but it's not something we should use in production.

We should try to find a reasonable authentication way using service account. I think it's possible to inject it into kubernetes client.