common: upgrade/install ceph-test deb first

common: upgrade/install ceph-test deb first

When we deploy a Jewel cluster on Ubuntu with ceph_test: True, we're
unable to upgrade that cluster to Luminous.

"apt-get install ceph-common" fails to upgrade to luminous if a jewel ceph-test package is installed:

  Some packages could not be installed. This may mean that you have
  requested an impossible situation or if you are using the unstable
  distribution that some required packages have not yet been created
  or been moved out of Incoming.
  The following information may help to resolve the situation:

  The following packages have unmet dependencies:
   ceph-base : Breaks: ceph-test (< 12.2.2-14) but 10.2.11-1xenial is to be installed
   ceph-mon : Breaks: ceph-test (< 12.2.2-14) but 10.2.11-1xenial is to be installed

In ceph-ansible master, we resolve this whole class of problem by
installing all the packages in one operation (see
b338fafd90bbe489726b92d703bf4bc29d1caf6d).

For the stable-3.1 branch, take a less-invasive approach, and upgrade
ceph-test prior to any other package. This matches the approach I took
for RPMs in 3752cc6f38dbf476845e975e6448225c0e103ad6, before we had the
better solution in b338fafd90bbe489726b92d703bf4bc29d1caf6d.

Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1610997
Signed-off-by: Ken Dreyer <kdreyer@redhat.com>