Python3.7 upgrading and TypeError: TypeError: can't multiply sequence by non-int of type 'float'

[felipe-dap]

Cheers everyone and thanks for the effort on making this available for everyone.
Since I needed to run it on Python 3.7 I had to adjust a few things.

1. Adjusting relative imports,

2. Class Node from gtfl2
   Line 11 -> unicode has to be changed to str for Python 3.

3. Class Skin from gtfl2
   Remove import Set from sets, as it is built-in for Python 3.
   change Set to set on the file, whenever it has called. If I remember it correctly, it was called just once.

4. gltf2usd.py
   On line 396 I had to force indices length/3 to return an integer as follows.
   num_faces = int(len(indices)/3)

Otherwise I ran into this:
Traceback (most recent call last):
File "gltf2usd.py", line 924, in
- irrelevant part -
face_count = [3] * num_faces
TypeError: can't multiply sequence by non-int of type 'float'

With this simple changes I could manage to make it work effortless.
Leaving this remarks in case someone needs it. =)
Mantainers can close this issue. This is just in case someone runs into this as well and need some guidance.
Thanks once again for the amazing work here.