CBQE:0 Change remote cluster reference for destination cluster to 'source'

Change-Id: I3d3103c15974e7ea4d827b6c77cf9f5850940f16
Reviewed-on: http://review.couchbase.org/42578
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Aruna Piravi <aruna@couchbase.com>
Tested-by: Aruna Piravi <aruna@couchbase.com>