Bump ava from 2.3.0 to 2.4.0

Bumps [ava](https://github.com/avajs/ava) from 2.3.0 to 2.4.0.
- [Release notes](https://github.com/avajs/ava/releases)
- [Commits](avajs/ava@v2.3.0...v2.4.0)

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

Author: dependabot-preview[bot]