Update dependency prettier to v2.3.1

Author: renovate-bot

package-lock.json

@@ -46,7 +46,7 @@
     "cross-env": "7.0.3",
     "jest": "26.6.3",
     "nodemon": "2.0.7",
-    "prettier": "2.3.0",
+    "prettier": "2.3.1",
     "subscriptions-transport-ws": "0.9.18",
     "supertest": "6.1.3",
     "ts-jest": "26.5.6",