Laravelのログインをメールアドレス以外にする

AuthControllerに「protected $username = 'name';」を足す。

<?php

namespace Song2\Http\Controllers\Auth;

use Song2\User;
use Validator;
use Song2\Http\Controllers\Controller;
use Illuminate\Foundation\Auth\ThrottlesLogins;
use Illuminate\Foundation\Auth\AuthenticatesAndRegistersUsers;

class AuthController extends Controller
{
    /*
    |--------------------------------------------------------------------------
    | Registration & Login Controller
    |--------------------------------------------------------------------------
    |
    | This controller handles the registration of new users, as well as the
    | authentication of existing users. By default, this controller uses
    | a simple trait to add these behaviors. Why don't you explore it?
    |
    */

    use AuthenticatesAndRegistersUsers, ThrottlesLogins;

    protected $username = 'name';

    /**
     * Where to redirect users after login / registration.
     *
     * @var string
     */
    protected $redirectTo = '/';