roomservice: Allow following up tag references

            add_auth(githubreq)

            result = json.loads(urllib2.urlopen(githubreq).read())

            ## Try tags, too, since that's what releases use

            if not has_branch(result, default_revision):

                githubreq = urllib2.Request(repository['tags_url'].replace('{/tag}', ''))

                add_auth(githubreq)

                result = json.loads(urllib2.urlopen(githubreq).read())

            repo_path = "device/%s/%s" % (manufacturer, device)

            adding = {'repository':repo_name,'target_path':repo_path}