Restart policy if data volume is lost

[daniwhere]

Requested by ELASTIC project: dataClay should be able to detect that the data-volume was lost or is unaccessible and re-create it when possible, registering everything needed again.

We should check docker restart policies.

Maybe we need to allow dataclay-initializer service (the one that registers models and accounts...) to keep running and watching if there is a failure and register everything again?

@alexbarcelo ideas?