/// <summary>
        /// POST: api/Messages
        /// Receive a message from a user and reply to it
        /// </summary>
        public async Task <HttpResponseMessage> Post([FromBody] Activity activity)
        {
            if (activity.Type == ActivityTypes.Message)
            {
                Activity reply = BotService.HandleBotRequest(activity);
                await BotService.SendUserResponse(activity, reply);
            }
            else
            {
                HandleSystemMessage(activity);
            }

            var response = Request.CreateResponse(HttpStatusCode.OK);

            return(response);
        }