public async Task <IHttpActionResult> EditEmail(int userID, string oldEmail, string newEmail)
        {
            if (!ModelState.IsValid)
            {
                return(BadRequest(ModelState));
            }

            if (string.IsNullOrWhiteSpace(newEmail))
            {
                return(BadRequest());
            }

            if (string.IsNullOrWhiteSpace(oldEmail))
            {
                return(NotFound());
            }

            User user = await Task.Run(() => db.Users.Where((u) => u.Email.ToLower() == oldEmail.ToLower() && u.UserID == userID).FirstOrDefault());

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

            await db.EditUserEmail(oldEmail, newEmail);

            return(Ok());
        }