CBLT-42:  add windows builds to sync_gateway master

Change-Id: I8cfcc8d28fa8ee598f21452b7fedb9d6d34cd654
Reviewed-on: http://review.couchbase.org/37196
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>