fix: package.json & yarn.lock to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-BODYPARSER-7926860
- https://snyk.io/vuln/SNYK-JS-EXPRESS-7926867
- https://snyk.io/vuln/SNYK-JS-SEND-7926862
- https://snyk.io/vuln/SNYK-JS-SERVESTATIC-7926865

package.json

@@ -45,7 +45,7 @@
     "eslint-plugin-node": "^11.1.0",
     "eslint-plugin-standard": "^4.0.1",
     "eslint-plugin-typescript": "^0.14.0",
-    "express": "^4.16.4",
+    "express": "^4.20.0",
     "folder-hash": "^2.1.1",
     "fs-extra": "^9.0.1",
     "got": "^11.8.5",