Bump supertest from 3.0.0 to 3.3.0

Bumps [supertest](https://github.com/visionmedia/supertest) from 3.0.0 to 3.3.0.
- [Release notes](https://github.com/visionmedia/supertest/releases)
- [Changelog](https://github.com/visionmedia/supertest/blob/master/History.md)
- [Commits](ladjs/supertest@v3.0.0...v3.3.0)

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

package.json

@@ -45,7 +45,7 @@
     "nodemon": "1.12.1",
     "nyc": "^13.0.1",
     "sinon": "4.0.1",
-    "supertest": "3.0.0",
+    "supertest": "3.3.0",
     "tslint": "^5.11.0",
     "tslint-config-airbnb": "^5.11.0",
     "typescript": "3.0.3"