Add Python3 support

[matt852]

I would like to add Python3 support in NetConfig, and eventually phase out Python2 support.

[layertwo]

Would love to work on this. I was starting to look at it in a different branch in my fork.

[matt852]

I saw that branch, and decided to make an issue to track the progress. Thanks for your help.

[layertwo]

Are you able to assign this issue to me then?