Currently, Magnum is running periodic tasks to collect k8s cluster
metrics to message bus. Unfortunately, it's collecting pods info
only from "default" namespace which makes this function useless.
What's more, even Magnum can get all pods from all namespaces, it
doesn't make much sense to keep this function in Magnum. Because
operators only care about the health of cluster nodes. If they
want to know the status of pods, they can use heapster or other
tools to get that.
Task: 22619
Story: 1775116
Change-Id: I3ca0f2e96fe63870406cc5323f08fa018ac6e8be