Autograph-utils

<!-- Release notes generated using configuration in .github/release.yml at main -->

What's Changed
New Features
* Modernize repo by leplatrem in https://github.com/mozilla-services/python-autograph-utils/pull/29
* Test with Python 3.12 by leplatrem in https://github.com/mozilla-services/python-autograph-utils/pull/36

Other Changes
* staging root hash (bug 1691797) as of 2021-02-12 by hwine in https://github.com/mozilla-services/python-autograph-utils/pull/11
* Switch to GitHub actions by leplatrem in https://github.com/mozilla-services/python-autograph-utils/pull/14
* Run black 23.7.0 by leplatrem in https://github.com/mozilla-services/python-autograph-utils/pull/23

New Contributors
* hwine made their first contribution in https://github.com/mozilla-services/python-autograph-utils/pull/11
* dependabot made their first contribution in https://github.com/mozilla-services/python-autograph-utils/pull/10

**Full Changelog**: https://github.com/mozilla-services/python-autograph-utils/compare/0.1.1...0.2.0

- Fix call to ``_now`` (8).

I forgot to follow the process exactly for this release, so there was no "preparing 0.1.1" PR.

First release to PyPI: https://pypi.org/project/autograph-utils/