add url for sherlock builds

Change-Id: I48abb3e1e4749ba5c9696e753ae0833dcea6fa27
Reviewed-on: http://review.couchbase.org/44339
Reviewed-by: Venu Uppalapati <venumahesh@gmail.com>
Tested-by: Venu Uppalapati <venumahesh@gmail.com>