Verify that partitions (for both osd disks and journal disks) are sane
before attempting to prepare the device. Fail if parted fails for
whatever reason.
Closes: #437
Signed-off-by: Sébastien Han <seb@redhat.com>
This branch has been sitting on my local repo for a while. I guess I had
time to spend on a plane :).
Signed-off-by: Sébastien Han <sebastien.han@enovance.com>