chore(deps): bump tokio-test from 0.2.1 to 0.4.0

Bumps [tokio-test](https://github.com/tokio-rs/tokio) from 0.2.1 to 0.4.0.
- [Release notes](https://github.com/tokio-rs/tokio/releases)
- [Commits](https://github.com/tokio-rs/tokio/commits)

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

Author: dependabot[bot]