Enhancement: Run friendsofphp/php-cs-fixer on GitHub Actions

Co-authored-by: Markus Staab <maggus.staab@googlemail.com>

Closes GH-559.

.php-cs-fixer.php

@@ -0,0 +1,14 @@
+<?php
+
+$finder = PhpCsFixer\Finder::create()->in(__DIR__);
+
+$config = new PhpCsFixer\Config();
+
+$finder = $config->getFinder()
+    ->ignoreDotFiles(false)
+    ->in(__DIR__)
+    ->name(__FILE__);
+
+$config->setRules([]);
+
+return $config;