cross-env NODE_ENV=development webpack [Fixed]

In Laravel 5.4 there is no gulpfile.js file because everything's moved into the web pack now, the first time I ran
$npm run dev
I encountered this error.
cross-env NODE_ENV=development webpack --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js

Fix by installing the latest Node Js
sudo npm cache clean -f 
sudo npm install -g n
sudo n stable
Run this again to gulp your files
$npm run dev