slightly better helpers for creating cache and roundtripper
slightly better helpers for creating cache and roundtripper

Change-Id: I5b7fc3ac1d1e168c84c81c1f41f88557b12ecaba
Reviewed-on: http://review.couchbase.org/62718
Tested-by: Artem Stemkovski <15a0730a27c69f62ab86f2b6c639fca202166c02@couchbase.com>
Reviewed-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>

couchbase/cbauth,couchbase/cbauth