MB-10415 use temp auth token for cluster join

Change-Id: Ib50f91f6789815302f55ca50c164e21d339deeef
Reviewed-on: http://review.couchbase.org/34787
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Tested-by: Artem Stemkovski <artem@couchbase.com>