Add Pylint

[juanjosalvador]

Add Pylint

[Euklios]

I just checked some of the pylint default warnings and got some questions:

How should we treat API changes?
For example: Nyaa.get and SukebeiNyaa.get have an inconsistently named parameter called id (or view_id in Nyaa.get). If we renamed that to view_id, which would be more specific, code like sukebei_nyaa.get(id="123") would break.

How should we handle the integration/automation of pylint?
The simplest thing would be running it manually; this is already possible.
We could also include it in a Pre-commit hook or run it from the CI. While the last option might be harder to set up, it could be interesting, depending on the number of automated tests planned.

We already talked about Pantsu; remove it from the project?
I don't want to investigate warnings in places that will be deleted anyway.

[JuanjoSalvador]

I'll take this, and I'm gonna think about how we can deal with this. At this moment I have some fixes on my local branches, but it needs some design changes.