Change setUpClass/tearDownClass

Apparently py.test only recognizes these purely camelCase names, rather
than setupClass/teardownClass

Change-Id: Ia520e318f8ccf7f66c25604d92a1a0486d3ef835
Reviewed-on: http://review.couchbase.org/29308
Reviewed-by: Pavel Paulau <pavel.paulau@gmail.com>
Tested-by: Mark Nunberg <mnunberg@haskalah.org>