Update dependency supertest to v6.1.6

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
supertest	6.1.5 -> 6.1.6

---

Release Notes

visionmedia/supertest

### [`v6.1.6`](https://togithub.com/visionmedia/supertest/releases/v6.1.6) [Compare Source](https://togithub.com/visionmedia/supertest/compare/v6.1.5...v6.1.6) - Merge pull request [#​735](https://togithub.com/visionmedia/supertest/issues/735) from benjosantony/master [`28116f9`](https://togithub.com/visionmedia/supertest/commit/28116f9) - Add on to the mitigation in [https://github.com/visionmedia/supertest/pull/728](https://togithub.com/visionmedia/supertest/pull/728)/commits to support empty array response body [`ed0f68d`](https://togithub.com/visionmedia/supertest/commit/ed0f68d)

---

Configuration

📅 Schedule: At any time (no schedule defined).

🚦 Automerge: Enabled.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• [ ] If you want to rebase/retry this PR, check this box.

---

This PR has been generated by WhiteSource Renovate. View repository job log here.