Set PHP-CS-Fixer cache path in config

Author: ezzatron

.php_cs

@@ -1 +1,6 @@
-<?php return Eloquent\CodeStyle\Config::create(__DIR__);
+<?php
+
+$config = Eloquent\CodeStyle\Config::create(__DIR__);
+$config->setCacheFile(__DIR__ . '/artifacts/lint/php-cs-fixer/cache');
+
+return $config;