`ceph-docker-common`:
At the moment there is a lot of duplicated tasks in each
`./roles/ceph-<role>/tasks/docker/main.yml` that could be refactored in
`./roles/ceph-docker-common/tasks/main.yml`.
`*_containerized_deployment` variables:
All `*_containerized_deployment` have been refactored to a single
variable `containerized_deployment`
duplicate `cephx` variables in `group_vars/* have been removed.
Signed-off-by: Guillaume Abrioux <gabrioux@redhat.com>