Autoload PHPActiveRecord to work with Silex

ActiveRecordServiceProvider.php

<?php

/*
 * Author: Dwi Sasongko S <[email protected]>
 * See: http://www.phpactiverecord.org/projects/main/wiki/Quick_Start
 */

namespace App\Provider;

use Silex\Application;
use Silex\ServiceProviderInterface;

class ActiveRecordServiceProvider implements ServiceProviderInterface
{
    private $app;

    public function register(Application $app)
    {
        $this->app = $app;

        \ActiveRecord\Config::initialize(function ($cfg) use ($app) {
                $cfg->set_model_directory($app['base_dir'] . '/app/' . $app['name'] . '/Model');
                $cfg->set_connections(array(
                    'development' => 'mysql://root@localhost/db_name',
                ));
                $cfg->set_default_connection('development');
            });
    }

    public function boot(Application $app)
    {}
}

composer.json

{
    "repositories": [
        {
            "type": "package",
            "package": {
                "name": "kla/php-activerecord",
                "version": "dev-master",
                "autoload": {
                    "psr-0": {
                        "ActiveRecord": "lib/"
                    },
                    "files": [
                        "ActiveRecord.php"
                        ]
                },
                "source": {
                    "url": "https://github.com/kla/php-activerecord",
                    "type": "git",
                    "reference": "master"
                }
            }
        }
     ],
    "require": {
       "php-activerecord/php-activerecord": "dev-master"
    }
}

Problem.php

<?php

namespace App\Model;

class Problem extends \ActiveRecord\Model
{
    static $belongs_to = array(
        array('user')
    );
}

User.php

<?php

namespace App\Model;

class User extends \ActiveRecord\Model
{
    static $connection = 'development';

    static $attr_accessible = array('name', 'surname', 'destiny');

    static $alias_attribute = array(
        'alias_name' => 'name',
        'alias_surname' => 'surname',
        'alias_destiny' => 'destiny'
    );

    static $has_many = array(
        array('problem'),
        array('affair')
    );
}