Update dependency supertest to v6.2.1

Author: renovate-bot

package-lock.json

@@ -48,7 +48,7 @@
     "nodemon": "2.0.15",
     "prettier": "2.5.1",
     "subscriptions-transport-ws": "0.11.0",
-    "supertest": "6.1.6",
+    "supertest": "6.2.1",
     "ts-jest": "26.5.6",
     "ts-node": "10.4.0",
     "ts-node-dev": "1.1.8",