Unable to compile test suite on windows host

[akashihi]

Dev build depends on linux-embedded-hal which brings non-portable crates, such as gpio-cdev, spidev, sysfs-gpio and serial-unix which prevents compilation and execution of unit tests on windows.

As linux-embedded-hal is only used for the example code, both example code build and linux-embedded-hal dependency could be a default feature, which can be disabled on the windows platform.

[caemor]

I tried to fix this today by making linux-embedded-hal an optional dev-dependency but this is currently not possible (see rust-lang/cargo#1596).
One possible solution would be the move to an optional dependency which makes it worse from my point of view.
Another solution might be the move to a workspace and to move the examples to their own "crate".

I would be happy to receive some feedback and maybe an even better and more elegant solution for this problem.

EDIT: Should be fixed in #101