[CBD-1249]: Pass latest build number dynamically to smoke_test.sh

Change-Id: Iae32fef9b613159ec96f6fb90c37c8fcec94cfaf
Reviewed-on: http://review.couchbase.org/34390
Tested-by: Eric Limare <eric.limare@couchbase.com>
Reviewed-by: Eric Limare <eric.limare@couchbase.com>