This is from the case I originally got to trigger the problem. We could
probably boil it down to something smaller (by temporarily reverting the
Orient2d change to make sure the failure still occurs) but this doesn't
seem too bloated for a unit test as-is.
- Building unit tests is optional, disabled by default to prevent
the library clients from pulling the dependency on boost
- Add the unit tests to the Github Actions.
- Use boost::filesystem to manipulate paths for better portability
