fix: upgrade prettier from 2.3.2 to 2.4.0 (#419)

Snyk has created this PR to upgrade prettier from 2.3.2 to 2.4.0.

See this package in npm:
https://www.npmjs.com/package/prettier

See this project in Snyk:
https://app.snyk.io/org/kpt-fn-bot/project/046a0d33-b384-4105-962d-be6f1db5074a?utm_source=github&utm_medium=referral&page=upgrade-pr

Author: snyk-bot

ts/demo-functions/package-lock.json

@@ -37,7 +37,7 @@
     "fs-extra": "^9.0.1",
     "jasmine": "^3.9.0",
     "license-checker": "^25.0.1",
-    "prettier": "2.3.2",
+    "prettier": "2.4.0",
     "tslint": "^6.1.3",
     "tslint-config-prettier": "1.18.0",
     "tslint-consistent-codestyle": "^1.16.0",