Bump serve from 1.4.0 to 7.1.3

Bumps [serve](https://github.com/zeit/serve) from 1.4.0 to 7.1.3.
- [Release notes](https://github.com/zeit/serve/releases)
- [Commits](https://github.com/zeit/serve/commits/7.1.3)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]