chore(deps): update dependency eslint-plugin-node to v9 (#342)

Author: renovate[bot]

packages/google-cloud-node/package.json

@@ -55,7 +55,7 @@
     "codecov": "^3.0.2",
     "eslint": "^5.0.0",
     "eslint-config-prettier": "^4.0.0",
-    "eslint-plugin-node": "^8.0.0",
+    "eslint-plugin-node": "^9.0.0",
     "eslint-plugin-prettier": "^3.0.0",
     "jsdoc-baseline": "git+https://github.com/hegemonic/jsdoc-baseline.git",
     "intelli-espower-loader": "^1.0.1",