Update dependency express to v4.20.0 [SECURITY]

Author: renovate[bot]

package.json

@@ -54,7 +54,7 @@
     "apollo-server-express": "2.6.3",
     "core-js": "3.1.3",
     "cors": "2.8.5",
-    "express": "4.17.1",
+    "express": "4.20.0",
     "graphql": "14.3.1",
     "graphql-subscriptions": "1.1.0",
     "graphql-tools": "4.0.5",