Implement upgrade strategies using k8s 'deployment' objects

[mafraba]

See http://kubernetes.io/v1.1/docs/user-guide/deployments.html

[mafraba]

Downside: extension API, which means it is not enabled by default in a cluster

[mafraba]

Forget about v1.1 deployments and previous comments.

Deployments are now a fundamental part of k8s 1.2