CI on Mac & Windows are not building the python bindings

[lgritz]

Looks like our Mac- and Windows-based CI tests are not building or testing the python bindings. (The Linux ones are.)

[cary-ilm]

@xlietz, we raised this issue in the TSC meeting today and can't remember if there were good reasons to omit python from the macOS and Windows builds. Are there issues with boost? If it's not too much hassle, it would be good to have at least one of passes for macOS and Windows build the bindings.

[xlietz]

@cary-ilm it isn't possible on the Windows build since the only way would be to get the Boost source and build (the issue we had more than a year ago). There should be Mac builds with python though. I'll take a look when I work on adding the Linux no-python builds.