Support the Kubernetes API as a topology service

[carsonoid]

Feature Description

Right now running even a small Vitess installation in Kubernetes requires that the end user deploy and maintain a fully functional kv store. It seems to be a hurdle for initial adoption for many users.

Since the Kubernetes API is built on etcd and provides all the same primitives (get, update, delete, watch, lock) it should be possible to use the K8s as a topology service.

Use Case(s)

Any user running Vitess in Kubernetes.