public async Task <IHttpActionResult> EditPassword(int userID, string oldPassword, string newPassword)
        {
            if (!ModelState.IsValid)
            {
                return(BadRequest(ModelState));
            }

            var user = await db.Users.FirstOrDefaultAsync((u) => u.UserID == userID);

            if (user == null)
            {
                return(NotFound());
            }

            await db.EditUserPassword(userID, oldPassword, newPassword);

            return(Ok());
        }