fix(deps): update dependency yargs to v13 (#312)

Author: renovate[bot]

error-reporting/package.json

@@ -17,7 +17,7 @@
   "dependencies": {
     "@google-cloud/error-reporting": "^0.6.0",
     "express": "^4.16.3",
-    "yargs": "^12.0.0"
+    "yargs": "^13.0.0"
   },
   "devDependencies": {
     "@google-cloud/nodejs-repo-tools": "^3.0.0",