Use pyproject.toml instead of setup.cfg

[leouieda]

Description:

setuptools now allows defining all of the package data in pyproject.toml so we should do that instead of defining things in setup.cfg. The main problem is flake8 doesn't yet allow configuration in pyproject.toml so it will need a .flake8 config files of its own.

This also requires updating dependente to v0.3.0 in the GitHub Actions.

See the files in the repos that are done for a reference.

Apply to:

• boule
• harmonica
• pooch
• verde
• ensaio
• choclo
• dependente
• burocrata

Further instructions:

• Start by opening Pull Requests on each repository listed above.
• Optionally, we can open Issues on each repository if further discussion specific to that repository is needed.
• Mention this Issue on every Issue or Pull Request opened on each opened: Related to fatiando/community#143
• Check-off the repository on the list above once the Pull Request is merged.
• Close this issue when all items are checked-off.

We want your help!

We know that maintenance tasks are very demanding, so we don't expect a single person to tackle this issue by themselves. Any help is very welcomed, so please comment below that you want to take care of the changes on any repository and we will assign it to you.