How to use \Phalcon\Loader to autoload namespace.

Phalcon-Loading-Namespaces

<?php 

define('ROOT_PATH', __DIR__.'/../');
define('APP_PATH', ROOT_PATH.'app/');

// Registering an auto-loader
$loader = new \Phalcon\Loader();

$loader->registerNamespaces(
    array(
        'Controllers'  => APP_PATH.'Controllers/',
    )
);

$loader->register();