public function destroy($id, User $user)
 {
     $help = Help::find($id);
     $log = new Log();
     $log->user_id = $user->id;
     $log->log = "删除帮助" . print_r($help->toArray(), true);
     $log->save();
     Help::destroy($id);
     return redirect()->action('AdminController@getHelp');
 }