public void Update(int id, string title, string description, int creator, int contractor)
        {
            var users = new UserRepository();
            var tasks = new TaskRepository();
            var t     = tasks.FindById(id);

            t.Title       = title;
            t.Description = description;
            t.Creator     = users.FindById(creator);
            t.Contractor  = users.FindById(contractor);
            SaveChanges();
        }