Enable previously broken test.
Enable previously broken test.

CouchbaseMock has been updated with support for this particular
feature, and thus it is safe to turn the test back on.

Change-Id: I95687e9c1c1fe735a886f9960e9322ae599bf7ec
Reviewed-on: http://review.couchbase.org/81030
Reviewed-by: Michael Nitschinger <17b9e1c64588c7fa6419b4d29dc1f4426279ba01@nitschinger.at>
Tested-by: Brett Lawson <c8c4369773d7d7226e031f0c4af62e3f38a08510@gmail.com>

brett19/gocb