Remove the vendor directory in .gitignore as these dependencies are needed for php-imap

plugins/php-imap/vendor/illuminate/contracts/Mail/Attachable.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace Illuminate\Contracts\Mail;
+
+interface Attachable
+{
+    /**
+     * Get an attachment instance for this entity.
+     *
+     * @return \Illuminate\Mail\Attachment
+     */
+    public function toMailAttachment();
+}