Latest embedded-hal@1 alpha removes CountDown

[ahdinosaur]

Maybe worth mentioning, embedded-hal@1.0.0-alpha.7 removes CountDown, which this library depends on.

rust-embedded/embedded-hal#324

[hannobraun]

Thanks for letting me know, @ahdinosaur. That's certainly a problem.

I wouldn't expect this situation to resolve itself near-term, so just sitting the problem out is probably not a solution. We might need to define our own traits and require users to implement them on their target platform.

Unfortunately I don't have much capacity to deal with this issue. This is something that would need to be driven by contributors.