Bump superagent from 5.3.1 to 6.0.0 in /packages/health-check

Bumps [superagent](https://github.com/visionmedia/superagent) from 5.3.1 to 6.0.0.
- [Release notes](https://github.com/visionmedia/superagent/releases)
- [Changelog](https://github.com/visionmedia/superagent/blob/master/HISTORY.md)
- [Commits](https://github.com/visionmedia/superagent/compare/v5.3.1...v6.0.0)

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

packages/health-check/package.json

@@ -10,7 +10,7 @@
     "lodash": "^4.17.19",
     "lowdb": "^1.0.0",
     "node-schedule": "^1.3.2",
-    "superagent": "^5.3.1"
+    "superagent": "^6.0.0"
   },
   "devDependencies": {
     "prettier": "^2.0.5"