Added unit tests for UPR consumer mutate and delete.

Change-Id: Ide5d723c8a19235ab749ce01a3d8b84035ddce13
Reviewed-on: http://review.couchbase.org/29906
Reviewed-by: Michael Wiederhold <mike@couchbase.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>