Bump bytes from 1.2.0 to 1.2.1

Bumps [bytes](https://github.com/tokio-rs/bytes) from 1.2.0 to 1.2.1.
- [Release notes](https://github.com/tokio-rs/bytes/releases)
- [Changelog](https://github.com/tokio-rs/bytes/blob/master/CHANGELOG.md)
- [Commits](https://github.com/tokio-rs/bytes/commits)

---
updated-dependencies:
- dependency-name: bytes
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>