chore(deps): update dependency @types/node to v8.9.1

Author: renovate-bot

package.json

@@ -28,7 +28,7 @@
   },
   "devDependencies": {
     "@types/graphql": "0.11.7",
-    "@types/node": "8.5.2",
+    "@types/node": "8.9.1",
     "typescript": "2.6.2"
   }
 }