CBQE-927: offline_cluster_upgrade with rm manifest

Change-Id: Ibac0cd5a95a0486979f9305f70cc9beb1451c7d5
Reviewed-on: http://review.couchbase.org/23877
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>