Todo
* Write README
* Move to openstack-charmers
* security checklist
* zaza tests for pause/resume
* remove hardcoded password
* switch to mod_wsgi

* Refactor ceph broker code in charm helpers
* Rewrite ceph-client interface to stop using any relation* commands via charmhelpers
* Ceph heartbeat settings https://docs.ceph.com/docs/master/rbd/iscsi-requirements/

Mostly Done
* Certificates interface
* trusted_ips
* zaza tests for creating nd mounting a target
* Implement pause/resume
* Add iscsi target create action
* admin password
* implement source config option
* Proper Update Status
* Fix workload status so it reports missing relations
* Write spec
* Remove hardcoded ceph pool name and expose as a config option
* Add series upgrade