Laravel 5.6 updates

Travis config update

Removed HHVM script as Laravel no longer support HHVM after releasing 5.3

vendor/symfony/finder/Exception/ExceptionInterface.php

@@ -1,25 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\Finder\Exception;
-
-/**
- * @author Jean-François Simon <contact@jfsimon.fr>
- *
- * @deprecated since 3.3, to be removed in 4.0.
- */
-interface ExceptionInterface
-{
-    /**
-     * @return \Symfony\Component\Finder\Adapter\AdapterInterface
-     */
-    public function getAdapter();
-}