chore(deps): update dependency mocha to v7 (#428)

Author: renovate-bot

error-reporting/package.json

@@ -20,6 +20,6 @@
   "devDependencies": {
     "chai": "^4.2.0",
     "gaxios": "^2.0.1",
-    "mocha": "^6.0.0"
+    "mocha": "^7.0.0"
   }
 }