public ActionResult AddChallenge(Challenge challenge)
        {

            RavenService.SaveChallenge(RavenSession, challenge);

            return RedirectToAction("AddChallenge");
        }
        public static void SaveChallenge(IDocumentSession session, Challenge challenge)
        {
           challenge.Single = true;
           challenge.Category = ChallengeCategory.Miscellaneous;
           session.Store(challenge);
           session.SaveChanges();

        }
 public ActionResult AddChallenge()
 {
     var model = new Challenge();
     return View(model);
 }