NCBC-275: Modify Nunit tests to allow for execution in single node environment.

Change-Id: Ib4a95b1f70f7d248fa0bfbff22ebb7199a3187d7
Reviewed-on: http://review.couchbase.org/26997
Reviewed-by: Mordechai Nunberg <mnunberg@haskalah.org>
Reviewed-by: Saakshi Manocha <saakshi.manocha@globallogic.com>
Tested-by: Saakshi Manocha <saakshi.manocha@globallogic.com>