Composer update

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

vendor/psy/psysh/test/fixtures/config.php

@@ -0,0 +1,20 @@
+<?php
+
+/*
+ * This file is part of Psy Shell.
+ *
+ * (c) 2012-2018 Justin Hileman
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+$config->setRuntimeDir(\sys_get_temp_dir() . '/psysh_test/withconfig/temp');
+
+return [
+    'useReadline'       => true,
+    'usePcntl'          => false,
+    'requireSemicolons' => false,
+    'useUnicode'        => true,
+    'errorLoggingLevel' => E_ALL & ~E_NOTICE,
+];