Fix #32

[JulianOrteil]

Addresses #32.

I also changed docstrings to better conform to PEP257. The style I chose should conform nicely to sphinx as I wasn't able to determine a standard set with this library.

[FoamyGuy]

Thanks for working on this @JulianOrteil!

I have a few changes to request. We'll try to get this tested out as well to ensure some of the new type annotations that haven't been used before won't cause trouble.

[JulianOrteil]

@FoamyGuy Other adafruit libraries use the sphinx docstring style (i.e. :param int myvariable: A description of myvariable). Do you wish for me to use this style here?

[FoamyGuy]

@JulianOrteil Yes, thank you. We use sphinx to build the documentation pages, so we should follow that syntax.

[JulianOrteil]

@FoamyGuy All changes have been implemented. Depending on your answer to my question on 105 and 106, this PR should be ready to merge at your leisure :)

[FoamyGuy]

Looks good to me. Thanks for all of your work on this @JulianOrteil!