CBQE-0: Fixed test summary to dump in single xml file

Change-Id: Id07670b09ee285fb491c2d8bc5213fe09ed2b2c7
Reviewed-on: http://review.couchbase.org/35231
Reviewed-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>
Tested-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>