prepare release v1.9.1

prepare release v1.9.0

prepare release v1.8.0

run teardown_suite even in case of error in setup_suite

Try to handle syntax error in tests the best we can

Improve fake robustness. Stop supporting Debian. Start supporting NixOS

FIX issue with set -u

Add setup_suite and teardown_suite for file level setup/teardown

bash_unit changes the current working directory before loading the te…

…st file

One can now declare todo tests that are not yet implemented