CBLT-170:  need to define CBFS_URL

Change-Id: I4dacbe2096ea4fb2dd7b8aa49029a3612f172df9
Reviewed-on: http://review.couchbase.org/35737
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>