Wont build on python 2

[reconbot]

Half of the prebuildify-cross images use python 2 prebuild/docker-images#15 so we can't build on them. I'm not sure why however.

[thegecko]

Linked PR fixes this issue, but if you want to use different cross-build images (e.g. with python3 installed), you'll need to roll your own containers.

See here for example:

https://github.com/node-usb/docker-images

[reconbot]

I like the node-usb docker images, any reason we couldn't use those?

[thegecko]

I like the node-usb docker images, any reason we couldn't use those?

They won't contain python3 :)

They were needed to add the libudev-dev compilation dependency