// PUT: api/Roles/5
        public async Task <HttpResponseMessage> Put(string id, [FromUri] string userId)
        {
            HttpResponseMessage response;

            try
            {
                await _rolesService.ChangeRole(userId, id);

                response = Request.CreateResponse(HttpStatusCode.OK);
            }
            catch (Exception e)
            {
                Debug.WriteLine(e);
                response = Request.CreateResponse(HttpStatusCode.InternalServerError, e.Message);
            }

            return(response);
        }