Dynamic Ceph Users

Create a vault plugin to dynamically manage ceph users.

Scope

Can be configured in vault with a root user account that will perform all of the actions
Configure roles/profiles for normal ceph users in the plugin
- Contain the capabilities a user account should have
- Can be used to create a user in ceph on the fly, obtaining the secret key and caps as a response
Configure roles/profiles for rgw ceph users in the plugin
- Contain the permissions an account should have
- Either creates new accounts or just extra keys (unsure for now)