CBLT-319:  if release and version are same (e.g. 1.0.1) then store
in s3://packages.couchbase.com/releases/couchbase-sync-gateway/{release}
or s3://packages.couchbase.com/releases/couchbase-lite/${product}/{release}

If they are different (e.g. release 1.0.1, version 1.0.1-beta) then last
segment is {release}/{version)  (e.g. 1.0.1/1.0.1-beta/)

Change-Id: I518a898e44ba27ca4106789cd1149abf4547815f
Reviewed-on: http://review.couchbase.org/38612
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>