hotfix: fixed gulp version

package.json

@@ -5,7 +5,7 @@
   "main": "gulpfile.js",
   "devDependencies": {
     "browser-sync": "^2.18.8",
-    "gulp": "^3.9.0",
+    "gulp": "3.9.1",
     "gulp-autoprefixer": "^3.1.0",
     "gulp-concat": "^2.6.1",
     "gulp-file-include": "^1.1.0",