mom: require latest mom version

Latest mom will support balloon_min needed for minimum guaranteed
memory. This patch makes vdsm dependant of the relevant version.

Change-Id: Ia88b2f0e992a09469fe14e6335782554525985b4
Signed-off-by: Doron Fediuck <dfediuck@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/17044
Reviewed-by: Dan Kenigsberg <danken@redhat.com>