Fix: add @types/node

Author: mysticatea

package.json

@@ -25,6 +25,7 @@
     "@types/estree": "0.0.35",
     "@types/lodash": "^4.14.68",
     "@types/mocha": "^2.2.41",
+    "@types/node": "^4.2.16",
     "babel-eslint": "^7.1.1",
     "chokidar-cli": "^1.2.0",
     "codecov": "^2.1.0",