pritunl: Mongo should be a statefulset as well

[victortrac]

We can't have more than 1 mongo, since we might as well put it in a StatefulSet. We should also rename replica_set.yaml and statefulset.yaml to just be what they are for: mongo.yaml and pritunl.yaml or whatever and then put in the resources required for each in the same file. That's clearer what the purpose is than the resource-type file names.

[techmexdev]

Renamed pritunl templates dir files: 3638879, and changed mongo to StatefulSet: 778db0a

[victortrac]

@rodolfo-r Have you tested this from scratch? Ideally, from a clean cluster like cloudkite-dev, we 1) delete the pritunl namespace 2) test tihs chart 3) delete the pods and see how they recover. Also, for public things like helm charts, we definitely should do PRs instead of simply merging.