fix: package.json & package-lock.json to reduce vulnerabilities (#88)

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-JSONWEBTOKEN-3180020
- https://snyk.io/vuln/SNYK-JS-JSONWEBTOKEN-3180022
- https://snyk.io/vuln/SNYK-JS-JSONWEBTOKEN-3180024
- https://snyk.io/vuln/SNYK-JS-JSONWEBTOKEN-3180026

package.json

@@ -35,7 +35,7 @@
     "form-urlencoded": "^6.1.0",
     "helmet": "^5.1.0",
     "ibm-watson": "^7.1.2",
-    "jsonwebtoken": "^8.5.1",
+    "jsonwebtoken": "^9.0.0",
     "mailgun.js": "^3.7.3",
     "microsoft-cognitiveservices-speech-sdk": "^1.24.1",
     "mysql2": "^2.3.3",