ceph-volume is a tool implemented in pure python, so it would be better
to make it a architecture independent package for better
maintainability.
in this change
* ceph-volume is extracted out into a separated package
* ceph-volume depends on ceph-osd, as it deploys it and relies on
an already-installed ceph-osd in the system.
* ceph-osd recommends ceph-volume. as ceph-osd can be used as a
standalone package. but ceph-volume enhances it. also, to ensure
the existing users to get ceph-volume installed along with
ceph-osd.
Signed-off-by: Kefu Chai <kchai@redhat.com>
