elixir version

package.json

@@ -6,7 +6,7 @@
   },
   "devDependencies": {
     "gulp": "^3.9.1",
-    "laravel-elixir": "^5.0.0",
+    "laravel-elixir": "^6.0.0-9",
     "bootstrap-sass": "3.3.6"
   }
 }