MB-43850 Update to allow return of CAS value for Set and Add calls
MB-43850 Update to allow return of CAS value for Set and Add calls

Change-Id: I281ef6739231dc7ef53848cea03ab2621daca75f
Reviewed-on: http://review.couchbase.org/c/go-couchbase/+/144511
Reviewed-by: Sitaram Vemulapalli <8d86a491dcdf321bac78bef141a8229a59bf9211@couchbase.com>
Reviewed-by: Marco Greco <63a03f5b14a94e811cf577897911ec77986e074a@couchbase.com>
Tested-by: Donald Haggart <693a38fcefea567bb88741c142b12e19c9ef6b34@couchbase.com>

couchbase/go-couchbase