Adding more design document tests.

Change-Id: Ife751f79c03a276423dcceab09ca17e9cbe67123
Reviewed-on: http://review.couchbase.org/40379
Reviewed-by: Michael Nitschinger <michael.nitschinger@couchbase.com>
Tested-by: Michael Nitschinger <michael.nitschinger@couchbase.com>