MB-100: fix offline_cluster_upgrade_non_default_path

with extra verification cases: bucket and view creaton after upgrade

Change-Id: Ibf3685f57305fc3f34de7c74efecf99e155dbe48
Reviewed-on: http://review.couchbase.org/24467
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: buildbot <build@couchbase.com>