MB-100: grouping in py-newupgrade.conf

Change-Id: Ic473286ede7fdc04a8a8605802e18a8450dc3710
Reviewed-on: http://review.couchbase.org/24469
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: Andrei Baranouski <andrei.baranouski@gmail.com>