Slack posting from M5Stack

Show this code just posting something to Slack channel by pushing the button on *M5Stack*
In loop() section, I’m using some magic numbers in order to clean up chattering. Those are different for each button, probably less stability of Button A… I’m not sure the reason why.
Anyway, I was really happy that I could finish this *basic and symbolic task* because it must be able to post to Slack if it’s named *IoT device* 😉