Generate css file in build folder using Webpack

@Shelob9 This generates the build version of index.scss, the clients/admin/build/style.min.css still needs to be enqueued and I'm not sure if we want to enqueue css files from the clients folder or move theme and enqueue from the assets folder.
BTW, the admin client is loading these styles via import within the index.js file, once we decide where we enqueue css from we can remove the import.

webpack.config.js

@@ -11,12 +11,8 @@ const ExtractTextPlugin = require( 'extract-text-webpack-plugin' );
 //Creates HTML for mounting using a PHP file
 const HtmlWebpackPlugin = require('html-webpack-plugin');
 
-
-// Main CSS loader for everything but blocks..
-const cssExtractTextPlugin = new ExtractTextPlugin({
-    // Extracts CSS into a build folder inside the directory current directory
-    filename: './build/[name]/build/style.min.css'
-});
+// Main CSS loader
+let cssExtractTextPlugin;
 
 // Configuration for the ExtractTextPlugin.
 // Handles CSS
@@ -57,6 +53,14 @@ entryPointNames.forEach( entryPointName => {
     externals[ '@/calderaForms' + entryPointName ] = {
         this: [ 'calderaForms', entryPointName ]
     }
+
+  // CSS loader for Admin client ( condition defines which client is using CSS loader )
+  if( entryPointName === 'admin' ){
+    cssExtractTextPlugin = new ExtractTextPlugin({
+      // Extracts CSS into a build folder inside the current directory
+      filename: './clients/' + entryPointName + '/build/style.min.css'
+    });
+  }
 } );
 
 // Define WordPress dependencies