Added support of Kubernetes API in magnum.
Added support of Kubernetes API in magnum.

This patch removes the use of Kubernetes CLI i.e kubectl
from magnum and adds the support of Kubernetes API.

Change-Id: Ibe7354abba962dde6855225471f468f6a19a41ff
Partially-Implements: blueprint python-k8sclient

dims/python-k8sclient