CBQE-1621 add test base class

Change-Id: Ia5956494596de51aaf679bf3e9b485ff40e74a7d
Reviewed-on: http://review.couchbase.org/30332
Reviewed-by: Thuan Nguyen <soccon@gmail.com>
Tested-by: Thuan Nguyen <soccon@gmail.com>