added dataaccess transaction

src/Utils/LuDataAccess.php

 
 namespace Luticate\Utils;
 
+use DB;
+
 abstract class LuDataAccess {
+
+    public static function transact(\Closure $function)
+    {
+        DB::transaction($function);
+    }
+
     /**
      * @param $data LuModel[]
      * @return LuDbo[]