object-storage: add UFO unit tests

Run the UFO unit tests following the main GlusterFS unit tests. The
UFO unit tests run under the Nose unit test running harness, requiring
the python-nose package to be installed. These unit tests run fast
enough that we could even consider running them on a commit hook run
by rfc.sh.

Note that they are not functional tests, as they don't require a real
Gluster file system to run.

Change-Id: I55972890c24be16fc588a6950cb6bfd539287bbe
Signed-off-by: Peter Portante <peter.portante@redhat.com>
Reviewed-on: http://review.gluster.org/4333
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
Reviewed-by: Anand Avati <avati@redhat.com>
Tested-by: Anand Avati <avati@redhat.com>