Issue #3137831 by opdavies: Use built-in Purge settings

package.json

@@ -11,7 +11,6 @@
   "dependencies": {
     "cross-env": "^5.2.0",
     "laravel-mix": "^5.0.1",
-    "laravel-mix-purgecss": "^5.0.0-rc.1",
     "tailwindcss": "^1.0.1"
   }
 }

tailwind.config.js

 module.exports = {
   prefix: '',
   important: false,
+  purge: [],
   theme: {
     extend: {},
   },

webpack.mix.js

 let glob = require('glob-all')
 let mix = require('laravel-mix');
 
-require('laravel-mix-purgecss')
-
 mix.postCss('src/tailwind.css', 'dist', [
   require('tailwindcss'),
 ])
-
-mix.purgeCss({
-  enabled: false, // Remove this line to enable PurgeCSS.
-  paths: () => glob.sync([
-    path.join(__dirname, '**/*.twig'),
-    '/var/www/sites/*/{modules,themes}/custom/**/*.twig'
-    '/var/www/{modules,themes}/custom/**/*.twig',
-  ]),
-  whitelistPatterns: [],
-  whitelistPatternsChildren: []
-})