Add persistent local storage support

[Olivier Berger]

It would be interesting to get some persistent local storage solution.

Minikube has one : https://github.com/kubernetes/minikube/blob/master/docs/persistent_volumes.md

It seems the one provided by rancher could be used too:
https://github.com/rancher/local-path-provisioner

[Olivier Berger]

Integrated the latter one