Support RBAC

[kuzznya]

Currently users have the full access to the cluster which is not the best for teams.
There should be an ability for admins to restrict users from deleting resources and to give a restricted access to other developers.
This list of roles should be ideally supported:

1. Administrator - full access
2. Developer - Read & Write, delete his own resources (?), do not delete stateful apps
3. ReadOnly - access service status & logs, restart the app (?)