Hi @sloria ,

thank you for the great extension for sphinx.
We want to use it with a custom gitlab instance (see #93), unfortunately github urls were hard coded in your version..

After looking inside the code I realized that with some modifications it could be handled much more flexible/customizable.

So I was so free to restructure the code a bit to allow proper customization.
Still the code remains fully backward compatible to existing settings.

Only exception is the commit role. To have a unified result it now also has the @ prefix, even for same repro links.

I hope you are okay with the changes and agree with the structure.

Tests were also added for the new features.

Note: I included the user role logic within the IssueRole logic. The github changelog is a bit confusing there.

I tried to change the travis settings to work with Python 3.10 but as @hugovk figured out traivs sucks ;-)
I saw that @hugovk experimented with github actions, looks good.

PS: I noticed that you still use user/password login for PyPi. AFAIK this is no longer supported/not recommended (instead people should use project specific tokens).

PSS: I can recomment https://pyscaffold.org/en/stable/ to set up further projects. It uses setuptools-scm to set versions -> very helpful :-)