ceph-dash 1.5

I recently played around with Rook on Kubernetes. This was so far my fastest Ceph cluster to setup. Since Rook provides some secrets and config maps already, I made the docker container for Ceph-dash compatible with their format. I also added Kubernetes deployment files in the contrib folder (tested on GKE, but should work on any Kubernetes cluster). No need to configure anything, they should just work out of the box.