Add tests for flexbox

[liZe]

The W3 test suite is a good source of inspiration.

[tokyovigilante]

Does anyone know of a way to run single tests? Either from the command-line or (preferably) in the debugger in VS Code?

[Tontyna]

Have a look at pytest doc

[liZe]

For the record: I have to update the documentation, but here's the way to add Pytest's options when launching tests with setup.py: you have to add the --addopts parameter.

For example: ./setup.py test --addopts='--no-cov -k test_float_text_indent'.