Bump socket.io from 2.2.0 to 2.4.0 (#2)

Bumps [socket.io](https://github.com/socketio/socket.io) from 2.2.0 to 2.4.0.
- [Release notes](https://github.com/socketio/socket.io/releases)
- [Changelog](https://github.com/socketio/socket.io/blob/2.4.0/CHANGELOG.md)
- [Commits](socketio/socket.io@2.2.0...2.4.0)

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

package-lock.json

@@ -17,7 +17,7 @@
     "heroku-ssl-redirect": "0.0.4",
     "nodemon": "^2.0.4",
     "serve-favicon": "^2.5.0",
-    "socket.io": "^2.2.0",
+    "socket.io": "^2.4.0",
     "twilio": "^3.34.0"
   },
   "devDependencies": {