Start user invite system

app/Exceptions/UserTokenExpiredException.php

@@ -0,0 +1,19 @@
+<?php namespace BookStack\Exceptions;
+
+class UserTokenExpiredException extends \Exception {
+
+    public $userId;
+
+    /**
+     * UserTokenExpiredException constructor.
+     * @param string $message
+     * @param int $userId
+     */
+    public function __construct(string $message, int $userId)
+    {
+        $this->userId = $userId;
+        parent::__construct($message);
+    }
+
+
+}