Remove user bio feature (#1214)

The feature is very limited in scope, and we hope for community
extensions to take over this feature and make it much better.

src/Event/UserBioWasChanged.php

@@ -1,37 +0,0 @@
-<?php
-
-/*
- * This file is part of Flarum.
- *
- * (c) Toby Zerner <toby.zerner@gmail.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Flarum\Event;
-
-use Flarum\Core\User;
-
-class UserBioWasChanged
-{
-    /**
-     * @var User
-     */
-    public $user;
-
-    /**
-     * @var User
-     */
-    public $actor;
-
-    /**
-     * @param User $user
-     * @param User $actor
-     */
-    public function __construct(User $user, User $actor = null)
-    {
-        $this->user = $user;
-        $this->actor = $actor;
-    }
-}