fix: package.json & package-lock.json to reduce vulnerabilities (#78)

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-LODASH-1018905
- https://snyk.io/vuln/SNYK-JS-LODASH-1040724

Co-authored-by: snyk-bot <[email protected]>

Author: codepunkt

package-lock.json

@@ -13,7 +13,7 @@
   "dependencies": {
     "fast-json-patch": "^2.2.1",
     "humps": "^2.0.1",
-    "lodash": "^4.17.20",
+    "lodash": "^4.17.21",
     "mongoose": "^5.10.7"
   },
   "devDependencies": {