This is based on
https://packaging.python.org/en/latest/guides/publishing-package-distribution-releases-using-github-actions-ci-cd-workflows/#defining-a-workflow-job-environment
. It's the sample config from there, with versions updated and
our project name substituted in the appropriate places. I dropped
the publish-to-testpypi bit because of
https://github.com/pypa/packaging.python.org/issues/804

 , and left
the Github release part left out for now. We can add that later if
we like, but we never published releases to Github before, so it
doesn't seem required yet. I also tweaked the conditionals a bit
to avoid running the build job on forks and publish only tags
that start with 'v', as that's our convention for versions.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 5.0.0 to 5.1.0.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](https://github.com/actions/setup-python/compare/v5.0.0...v5.1.0

)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

This was lost when Travis stopped working, so our coveralls data
is frozen in 2021. This should get it working again using
https://github.com/marketplace/actions/coveralls-github-action


and allow coveralls to post comments on PRs.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

This reverts commit 3addf1e3.

I think we can just do this now Python 3.12 is stable.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 4.8.0 to 5.0.0.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](https://github.com/actions/setup-python/compare/v4.8.0...v5.0.0

)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 4.7.1 to 4.8.0.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](https://github.com/actions/setup-python/compare/v4.7.1...v4.8.0

)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 4.7.0 to 4.7.1.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](https://github.com/actions/setup-python/compare/v4.7.0...v4.7.1

)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v3...v4

)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 4.6.1 to 4.7.0.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](https://github.com/actions/setup-python/compare/v4.6.1...v4.7.0

)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 4.6.0 to 4.6.1.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](https://github.com/actions/setup-python/compare/v4.6.0...v4.6.1

)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 4.5.0 to 4.6.0.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](https://github.com/actions/setup-python/compare/v4.5.0...v4.6.0

)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

This drops the travis-ci config and adds config for running tests
via tox in Github Actions. It also updates the list of envs in
tox.ini for recent Python 3 versions.

Signed-off-by: Adam Williamson <awilliam@redhat.com>