## Wndows builds

This uses `appveyor.yml` and https://ci.appveyor.com/project/johnkerl/miller.

Unfortunately, I understand next to nothing about what I'm doing here --
whenever the AppVeyor build breaks (and the Travis build doesn't) I end up
googling for various things in the
https://ci.appveyor.com/project/johnkerl/miller build-log output, then
iteratively updating `appveyor.yml` until I can get a build again.

If anyone has expertise in this area, I'd love to chat! :)
