* Attempt to provide allow failure for PHP8.1 unit tests
PHP8.1 Tests show as passed despite the errors, and it requires checking the actual output from the run to see what the rea result is; but I can live with that until github provides functionality for a proper allow_failure option
The plan is to keep Travis for a short while, until we are confident that
GitHub Actions work well enough for us. And after that we can remove Travis
entirely.
There is a bunch of duplicated things but it allows us to maximize
parallelismt to have results as soon as possible.
API documentation generation is still missing.
Adrien Crivelli
Mark Baker