(Feature proposal) Add configuration option to use custom requirements file location for specific folder

[GideonBear]

Sorry if the title is unclear, for example:
I have a folder tests, and a requirements file at tests/requirements.txt. The requirement pytest is used in tests, is listed in tests/requirements.txt but not in requirements.txt, so I get an I900 error.
I currently have tests/*: I900 in per_file_ignores, which works, but is a workaround, and it would be cool if this could be implemented in flake8-requirements.

[Dreamsorcerer]

Dupe: #13 (comment)

[GideonBear]

Dupe: #13 (comment)

Should I close this issue or is it fine if there's a separate issue for this?

[arkq]

You can keep this one open, more chance that someone will implement it (or me, if I will find some spare time).