chore(package): update eslint-plugin-node to version 6.0.0 (#36)

Author: greenkeeper[bot]

package.json

@@ -15,7 +15,7 @@
     "eslint": "^4.16.0",
     "eslint-config-standard": "^11.0.0-beta.0",
     "eslint-plugin-import": "^2.8.0",
-    "eslint-plugin-node": "^5.2.1",
+    "eslint-plugin-node": "^6.0.0",
     "eslint-plugin-promise": "^3.6.0",
     "eslint-plugin-standard": "^3.0.1",
     "mocha": "^5.0.0",