Fixing vulnerability reported by snyk (#51)

* Fixing vulnerability reported by snyk

That does not cause any harm to this samples package but I want to keep snyk dashboard clean.

* require the correct version of the main package

* undo version change

Author: alexander-fenster

error-reporting/package.json

@@ -19,7 +19,7 @@
   },
   "dependencies": {
     "@google-cloud/error-reporting": "0.2.1",
-    "express": "4.15.4",
+    "express": "4.16.0",
     "yargs": "8.0.2"
   },
   "devDependencies": {