public void Reserver(string idTrajet, string userId)
        {
            Trajet trajetReserver = serviceTrajet.GetTrajetById(idTrajet);

            //User manager n'est pas injectable. il va faloir trouver un autre facon d'avoir le user.

            //ApplicationUser user = this.applicationManager.FindById(User.Identity.GetUserId());
            ApplicationUser user = serviceClient.GetClient(userId);

            Reservation reservation = new Reservation();

            reservation.ClientId = user.Id;
            reservation.TrajetId = trajetReserver.Id;

            serviceReservation.CreateReservation(reservation);
        }