CBQE-0: minor improvements in BaseTestCase.setUp

Change-Id: I8cb5a2818f836b98dff8391460c32ccb67c6eb76
Reviewed-on: http://review.couchbase.org/30253
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: Andrei Baranouski <andrei.baranouski@gmail.com>