Updates the requirements on [polyserve](https://github.com/Polymer/tools) to permit the latest version. - [Release notes](https://github.com/Polymer/tools/releases) - [Commits](https://github.com/Polymer/tools/commits/polyserve@0.27.13) Signed-off-by: dependabot[bot] <support@dependabot.com>
Signed-off-by: Julius Härtl <jus@bitgrid.net>