Composer update

* updated Laravel to v5.6.38
* Added laravel tinker in dev dependencies

vendor/phpunit/php-file-iterator/.php_cs.dist

@@ -163,5 +163,6 @@ return PhpCsFixer\Config::create()
         PhpCsFixer\Finder::create()
         ->files()
         ->in(__DIR__ . '/src')
+        ->in(__DIR__ . '/tests')
         ->notName('*.phpt')
     );