Added the pre-commit ci job so it runs in CI and check, fast fail was not the only culprit.

The exit with error code 2 and no indication is very annoying, do you know how to fix this @sbrunner ?

I found the test module which caused an issue, but I didn't succeed in finding the exact cause of the error, and I should stop for this evening!

I think there's an underlying issue in requirement_detector because the directory structure is like this:

/home/pierre/prospector/tests/tools/pylint/pylint_configs/
├── multiple
│   ├── __init__.py
│   ├── pyproject.toml
│   ├── setup.cfg
│   └── testcode.py
├── pylintrc
│   ├── __init__.py
│   └── testcode.py
├── pylintrc2
│   ├── __init__.py
│   ├── pylintrc
│   └── testcode.py
└── pyproject
    ├── __init__.py
    ├── pyproject.toml
    └── testcode.py

And we're trying to reach /home/pierre/prospector/tests/tools/pylint/pylint_configs/setup.cfg (should probably be /home/pierre/prospector/tests/tools/pylint/pylint_configs/multiple/setup.cfg ?)

I get a pretty nice solution!