tests: call 'cleanup' at the end of each test (backport BZ 983975)

Some tests do not cleanup after themselves. That is bad behaviour and
makes it difficult to run single tests and verify the state of the
system afterwards.

Change-Id: I5cf80a4a996c691e6b82fd9ce9c711951dc26138
Signed-off-by: Kaleb S. KEITHLEY <kkeithle@redhat.com>
BUG: 1004756
Reviewed-on: http://review.gluster.org/5821
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Niels de Vos <ndevos@redhat.com>