CBLT-319:  sync gateway builds are now edition-specific

Change-Id: Ie09361a7ea1b28e1c9115f7256e5f599c91e6eab
Reviewed-on: http://review.couchbase.org/39019
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>