chore(package): update @types/node to version 11.9.1

Closes #38

Author: greenkeeper[bot]

package.json

@@ -65,7 +65,7 @@
     "@types/debug": "0.0.31",
     "@types/express": "4.16.0",
     "@types/helmet": "0.0.42",
-    "@types/node": "10.12.11",
+    "@types/node": "11.9.1",
     "@types/request": "2.48.1",
     "all-contributors-cli": "5.4.1",
     "husky": "1.2.0",