Build Ports - TypeError: unsupported type: <class 'NoneType'>

[Moondragon85]

I've got exactly the same problem as #31 (hence reusing the identical title). I tested version 0.1.1, 0.1.0 and 0.0.9, all with the same result.

Through trial and error I figured out that the error occurs when assigning type 0 (USB A 2.0) to any port. I changed those ports to type 3 (USB A 3.0) and now it works.

I guess there's a bug somewhere in the code (I didn't look for it) that somehow interprets 0 as None and then plistlib.py trips over it.