Move to Symfony Flex

The structure changed completely.
Bundles are gone. Everything is flatten in the folder `src`.
I separated import & api controllers to avoid _pollution_ in the main controller folder.

webpack.config.js

@@ -2,7 +2,7 @@ const path = require('path');
 
 function buildConfig(options) {
   const env = options.prod ? 'prod' : 'dev';
-  return require(path.resolve(__dirname, `app/config/webpack/${env}.js`));
+  return require(path.resolve(__dirname, `scripts/webpack/${env}.js`));
 }
 
 module.exports = buildConfig;