fix(deps): update dependency nconf to ^0.13.0

Author: renovate-bot

samples/package.json

@@ -20,7 +20,7 @@
     "express": "^4.17.1",
     "googleapis": "^150.0.1",
     "googleapis-common": "^8.0.2-rc.0",
-    "nconf": "^0.12.0",
+    "nconf": "^0.13.0",
     "open": "^8.0.0",
     "server-destroy": "^1.0.1",
     "uuid": "^10.0.0"