Koji-fedoramessaging-messages

This release includes the following changes:

- don't include `tox.ini` in the final binary package
- add the spec file to the repo
- add Packit integration
- update dependencies
- add CI with Github actions

The main point of this release is to set severity to DEBUG on message that were ignored by FMN.

This update resolves the following issues:

* [2 buildsys.task.state.change: None is not of type 'integer' ](https://github.com/fedora-infra/koji-fedoramessaging-messages/issues/6)
* [3 buildsys.task.state.change: 'Scratch image build results in: /mnt/koji/work/tasks/9833/97319833' is not of type 'null'](https://github.com/fedora-infra/koji-fedoramessaging-messages/issues/6)
* [4 The id property is reserved in Fedora Messaging](https://github.com/fedora-infra/koji-fedoramessaging-messages/issues/6)
* [5 rpm.sign message summary returns build NVR, rather than the rpm NVR](https://github.com/fedora-infra/koji-fedoramessaging-messages/issues/6)
* [6 make tag / untag messages more informative](https://github.com/fedora-infra/koji-fedoramessaging-messages/issues/6)