Hello,
I have try the new validation from 2.1 beta 2 release but it does not seem to work. Here is the code i have used:
namespace Invo\Models;
use Phalcon\Mvc\Model;
use Phalcon\Validation;
use Phalcon\Validation\Validator\Email as EmailValidator;
use Phalcon\Validation\Validator\Uniqueness as UniquenessValidator;
class Users extends Model
{
    public function validation()
    {
        $validator = new Validation();
        $validator->add(
            'email',
            new EmailValidator()
        );
        $validator->add(
            'username',
            new UniquenessValidator(
                [
                    'message' => 'Sorry, That username is already taken',
                ]
            )
        );
        return $this->validate();
    }
}I got this error: Wrong number of parameters\n#0 /var/www/html/ngsecure/app/models/Users.php(103): Phalcon\Mvc\Model->validate()\n#1