public function update(HelpRequest $helpRequest, $id, User $user)
 {
     $help = Help::findOrFail($id);
     $log = new Log();
     $log->user_id = $user->id;
     $log->log = "编辑帮助" . print_r($help->toArray(), true);
     $help->fill($helpRequest->all());
     $help->content = $helpRequest->input(\Editor::input());
     $help->save();
     $log->save();
     return redirect()->action('AdminController@getHelp');
 }