类& # 39;用户# 39;运行工匠迁移时未找到

我正在尝试运行

project$ php artisan migrate:refresh

但是得到错误

[Symfony'Component'Debug'Exception'FatalErrorException]
Class 'Users' not found

为什么我需要Users课程?我已经有了app/User.php:

<?php namespace App;
use Illuminate'Auth'Authenticatable;
use Illuminate'Database'Eloquent'Model;
use Illuminate'Auth'Passwords'CanResetPassword;
use Illuminate'Contracts'Auth'Authenticatable as AuthenticatableContract;
use Illuminate'Contracts'Auth'CanResetPassword as CanResetPasswordContract;
class User extends Model implements AuthenticatableContract, CanResetPasswordContract {
[...]

和我的迁移，database/migration/2015_05_27_143124_create_users_table:

<?php
use Illuminate'Database'Schema'Blueprint;
use Illuminate'Database'Migrations'Migration;
class CreateUsersTable extends Migration {
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('users', function(Blueprint $table)
        {
            $table->increments('id');
            $table->string('username')->unique();
            [...]
            $table->string('password', 60);
            $table->rememberToken();
            $table->timestamps();
        });
    }
    [...]

我的config/auth.php也有'model' => 'App'User'。我试着运行project$ composer dump-autoload。正在定义User类。为什么我需要一个Users类?