This commit does a couple of things:
* Avoid code duplication
* Clarify the code
* add more unit tests
* add myself to the author of the module
Signed-off-by: Sébastien Han <seb@redhat.com>
The --crush-device-class flag for ceph-volume is not available in luminous so lets
remove this testing option for now until it's more widely available.
Signed-off-by: Andrew Schoen <aschoen@redhat.com>