public function store(Request $request)
 {
     $this->validate($request, ['title' => 'required|unique:unit_groups|max:100']);
     $input = $request->all();
     UnitGroups::create($input);
     Helper::add(DB::getPdo()->lastInsertId(), 'added new unit group ' . $input['title'] . ' (ID ' . DB::getPdo()->lastInsertId() . ')');
     Session::flash('flash_message', $this->title . ' successfully added!');
     return Redirect::action('UnitGroupsController@index');
 }