Add a `pytest.ini`

[pmeier]

🚀 Feature

Add a pytest.ini.

Motivation

IMO, the default pytest configuration is horrible and leads to enormous tracebacks that carry almost no information. Example

Pitch

Let's add a pytest.ini to the root of the project configuring the output to a more usable state. We can use PyTorch core as base.

Alternatives

If we for some reason do not want to add this for everyone, we still should add the appropriate flags to our CI runs.

cc @seemethere @pmeier

[NicolasHug]

Sounds good to me, thanks for raising this. One thing that I found a bit annoying is the docstring printing, which can be really long for functions like assert_close.
Do you want to submit a PR @pmeier ?