Fixes for macOS.

[AndreasPantle]

It solves the issues:

#49
#27

[amanusk]

Thank you for the PR!
Sorry it took me so long to notice it. Need to check my notifications :)

I don't currently have hardware to test this on. What did you use to test this?
Thanks!

Edit:
Oh, I see, it tries to probe the sensors and not assume they are supported by psuitl. Yea, that should be the better approach.
I was trying to avoid necessary try-catches, but this is what needed in this case

[AndreasPantle]

I did a test on a MacBook Pro and an older MacMini. But I think it should't depending on the model.

I have no possibility to catch the errors in other cases. Guess it seems the only way, otherwise:

>>> import platform
>>> platform.system()
'Darwin'

But this wouldn't be better...?