Add option to parse tag

[darkdragon-001]

We have our git tags in the form of release/x.y.z. Would be nice if one could specify a regex to extract the version from the tag (e.g. like tag_regex in pypa/setuptools_scm.

[dolfinus]

Hello.

Sorry for late response.
I'm going to add a branch_callback option to the package. But before I should add tests to cover existing functions, just to be sure that my changes will not affect a previous workflow.

[dolfinus]

Tests are in the master branch now, going to implement this feature

[dolfinus]

I've added new branch_formatter option in latest release v1.8.1.
You can pass here regexp, e.g. release\/(?P<branch>.*), or callback function which should accept one argument with original branch name and return formatted one.

Here is a documentation with an example: https://setuptools-git-versioning.readthedocs.io/en/latest/options/branch_formatter.html