chore(package): update gulp to version 3.9.1

http://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -40,7 +40,7 @@
     "eslint-path-formatter": "^0.1.1",
     "eslint-plugin-new-with-error": "^1.1.0",
     "eslint-plugin-no-use-extend-native": "^0.3.1",
-    "gulp": "^3.9.0",
+    "gulp": "^3.9.1",
     "gulp-babel": "^6.0.0",
     "gulp-eslint": "^1.0.0",
     "gulp-istanbul": "^0.10.0",