chore(deps-dev): bump @types/supertest from 2.0.7 to 2.0.8 (#20)

Bumps [@types/supertest](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/supertest) from 2.0.7 to 2.0.8.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/supertest)

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