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

plugins/php-imap/vendor/illuminate/contracts/Support/Htmlable.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace Illuminate\Contracts\Support;
+
+interface Htmlable
+{
+    /**
+     * Get content as a string of HTML.
+     *
+     * @return string
+     */
+    public function toHtml();
+}