change gitignore

vendor/ramsey/collection/src/Exception/CollectionMismatchException.php

@@ -0,0 +1,24 @@
+<?php
+
+/**
+ * This file is part of the ramsey/collection library
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ *
+ * @copyright Copyright (c) Ben Ramsey <ben@benramsey.com>
+ * @license http://opensource.org/licenses/MIT MIT
+ */
+
+declare(strict_types=1);
+
+namespace Ramsey\Collection\Exception;
+
+use RuntimeException;
+
+/**
+ * Thrown when attempting to operate on collections of differing types.
+ */
+class CollectionMismatchException extends RuntimeException implements CollectionException
+{
+}