CBQE-0 :: Fix failing test cases - rebalance and failover

Change-Id: I105c7edfec705dc50c061aa427f282933658e6f0
Reviewed-on: http://review.couchbase.org/41264
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Parag Agarwal <agarwal.parag@gmail.com>
Tested-by: Parag Agarwal <agarwal.parag@gmail.com>