chore(deps): update dependency supertest to v4

Author: renovate-bot

sample/19-auth-jwt/package.json

@@ -42,7 +42,7 @@
     "jest": "23.6.0",
     "nodemon": "1.19.1",
     "prettier": "1.18.2",
-    "supertest": "3.4.2",
+    "supertest": "4.0.2",
     "ts-jest": "24.0.2",
     "ts-node": "8.1.0",
     "tsconfig-paths": "3.8.0",