chore(deps): update dependency linkinator to v2 (#358)

Author: renovate-bot

packages/google-cloud-monitoring/package.json

@@ -49,7 +49,7 @@
     "jsdoc": "^3.5.5",
     "jsdoc-fresh": "^1.0.1",
     "jsdoc-region-tag": "^1.0.2",
-    "linkinator": "^1.5.0",
+    "linkinator": "^2.0.0",
     "mocha": "^7.0.0",
     "prettier": "^1.7.4"
   }