Add 3.3. to clusterLevels

Add version 3.3. to clusterLevels, returned by VDSM as part
of engine calling getCapabilities. This allows to test 3.3
specific features from engine.

Change-Id: I4d4f3ec3d0e006c87849dc5c28d632f50e7c25f0
Signed-off-by: Deepak C Shetty <deepakcs@linux.vnet.ibm.com>
Reviewed-on: http://gerrit.ovirt.org/13236
Reviewed-by: Dan Kenigsberg <danken@redhat.com>