Bumps [supertest](https://github.com/visionmedia/supertest) from 6.1.6 to 6.3.3.
- [Release notes](https://github.com/visionmedia/supertest/releases)
- [Commits](https://github.com/visionmedia/supertest/compare/v6.1.6...v6.3.3)

---
updated-dependencies:
- dependency-name: supertest
  dependency-type: direct:development
  update-type: version-update:semver-minor
...
Signed-off-by: dependabot[bot] <support@github.com>