chore(package): update @types/node to version 11.10.0

Closes #26

Author: greenkeeper[bot]

package.json

@@ -56,7 +56,7 @@
     "node": ">=4.5"
   },
   "devDependencies": {
-    "@types/node": "^10.12.0",
+    "@types/node": "^11.10.0",
     "ava": "^0.25.0",
     "codecov": "^3.1.0",
     "concurrently": "^4.0.1",