upgrade node types

node 9 is no longer supported

Author: Almenon

package-lock.json

@@ -13,7 +13,7 @@
   "dependencies": {},
   "devDependencies": {
     "@types/mocha": "^5.2.5",
-    "@types/node": "^9.3.0",
+    "@types/node": "^10.5.2",
     "mocha": "^5.2.0",
     "mocha-appveyor-reporter": "^0.4.0",
     "should": "^13.2.1",