/**
  * @return \Illuminate\Http\RedirectResponse
  */
 public function getCallback()
 {
     $accessToken = $this->auth->getToken(\Input::get('code'));
     $user = $this->auth->getUser($accessToken['access_token']);
     // GitHubアカウントでログインさせる
     $result = \Auth::attempt(['name' => $user['login'], 'id' => $user['id']], true);
     if (!$result) {
         return \Redirect::action('home.index')->withErrors(['auth_error' => 'Forbidden.']);
     }
     return \Redirect::action('webmaster.index');
 }