r.info: migrate to pytest

[kritibirda26]

Create the required sample data, pytest fixtures and migrate r.info module from gunittest to pytest.

[echoix]

For a single fixture used by a single file, placing it in a conftest.py file, that isn't reused anywhere else, I think it is only hiding the magic pytest does (the conftest isn't directly imported by us) and readers/reviewers need to remember to go see another file.

So, to replace a series of setUpClass/setUp, using fixtures defined in the same test file seems more efficient.

What do others think?

I didn't really start looking at the conversion itself

[kritibirda26]

The existing pytest tests are currently using per module conftest.py so I added it as a separate file in this case too. I think for now it would be fine even if we moved the fixtures to the test file itself.

But in the future, when I have more understanding of the test requirements of various modules, I would like to factor common fixtures to a higher level to reduce code duplication.