public function register()
 {
     if (!$this->validate()) {
         return false;
     }
     $user = new User();
     $user->attributes = $this->attributes;
     $user->password = $user->passwordToHash($this->password);
     $user->role = UserRole::USER;
     if (!$user->save()) {
         $this->addErrors($user->getErrors());
         return false;
     }
     \Yii::$app->mailer->compose('@app/auth/mail/registration', ['user' => $user])->setTo($user->email)->send();
     return true;
 }