Though The I have completed this small demo. But I have not written any step by step tutorial on my Blog. Till then you can watch my video tutorial on this link >> Hello,https://goo.gl/dKufr2
We are simply connecting one LED to esp8266 in this video and then connecting to a MQTT broker called io.reteiot.com , which allows REST api based communication with Chatfuel, which is a chat bot services.
I tried ti simplify and open the code for every one. If any one still have any doubt, don't forget to ask in the video comment section.