add support for kubernetes probes

[JakubBarta]

Hi, I'd like to thank you for amazing library in the first place!

I'm using EndlessCommand in kubernetes and I'd love if it supported k8s' probes (they make sure command is not stuck) - by touching predefined file every 15 seconds, for example.

My question is - are you interesting in having this new class as a part of this repo?

Thanks for reply @mac-cain13