tests: call 'cleanup' at the end of each test

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: I4ac5401d790d6bc81e6975fd1384874b21d6cf8a
BUG: 983975
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: http://review.gluster.org/5328
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
Reviewed-by: Anand Avati <avati@redhat.com>