CBQE-2411- adding test for star/ring topology

Change-Id: I52449814d55211128e89cc1aebc1d9a2ef016b5b
Reviewed-on: http://review.couchbase.org/43295
Reviewed-by: Aruna Piravi <aruna@couchbase.com>
Reviewed-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>
Tested-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>