Reconfigure CI and Documentation

[Zeitsperre]

Overview

This Pull Request adds a linting step to the CI configuration and also adds a ReadTheDocs v2 configuration (needed since 2020).

Additional Information

I've set ReadTheDocs to build Pull Requests, but since this PR is coming from a fork, I don't think that ReadTheDocs's configuration will change until the changes here are merged to master.

Contribution Agreement

(as per https://github.com/geopython/pywps/blob/master/CONTRIBUTING.rst#contributions-and-licensing)

• I'd like to contribute [feature X|bugfix Y|docs|something else] to PyWPS. I confirm that my contributions to PyWPS will be compatible with the PyWPS license guidelines at the time of contribution.
• I have already previously agreed to the PyWPS Contributions and Licensing Guidelines

[coveralls]

coverage: 84.061%. remained the same
when pulling 758ba18 on Zeitsperre:CI-and-Documentation
into 31bf412 on geopython:main.

[Zeitsperre]

@cehbrecht It looks as though the webhook isn't synchronized properly on ReadTheDocs (I can't see the main branch as an option for builds). Think you could try resyncing the GitHub integration? (I would also need maintainer status on GitHub as well to do this myself.)

It can be found here: https://readthedocs.org/dashboard/pywps/integrations/81509/

[cehbrecht]

@Zeitsperre I tried to re-sync the github integration ... but it didn't help. RTD might got confused with the branches ... we have now a "main" branch ... not "master". Should we remove the integration and re-add it again? I have given you permissions on GitHub as well.

[Zeitsperre]

@cehbrecht I've sent a bug report through ReadTheDocs so hopefully I'll receive a response. This is very strange behaviour, but I'm sure they can help us out with this.