public virtual ActionResult Delete(string id)
 {
     if (id == null)
     {
         return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
     }
     var role = _db.Roles.First(r => r.Name == id);
     var model = new RoleViewModel(role);
     if (role == null)
     {
         return HttpNotFound();
     }
     return View(model);
 }
 public virtual ActionResult Index()
 {
     var rolesList = new List<RoleViewModel>();
     foreach(var role in _db.Roles)
     {
         var roleModel = new RoleViewModel(role);
         rolesList.Add(roleModel);
     }
     return View(rolesList);
 }