Add build number to py-xdcrupgrade

Change-Id: I3b34bcbf3cc15526d656d702f4f32312a89f0dab
Reviewed-on: http://review.couchbase.org/28833
Reviewed-by: Ketaki Gangal <ketakigangal@gmail.com>
Tested-by: Ketaki Gangal <ketakigangal@gmail.com>