/**
     * Отправляем email об активации
     * @param User $user
     */
    protected function sendActivationMail(User $user){
        $headers = 'MIME-Version: 1.0' . "\r\n"
                 . 'Content-type: text/html; charset=UTF-8' . "\r\n"
                 . 'From: Framekit <robot@'. $_SERVER['SERVER_NAME'] . '>' . "\r\n";
        $text = $this->renderPartial('activation_letter', array('code'=>$user->getActivationCode(), 'id'=>$user->id), true);
        mail($user->email, 'Активация аккаунта Framekit', $text, $headers);
    }