check_mumble_ping

What's Changed

• Change output format (to enable formatting in Icinga2)
• Improve error handling except e: probably never worked
• Add testcases for all functions
• Add linter and fix linting issues
• Add version output
• Add GitHub Action configuration
• Update .gitignore
• Add tests and refactor for testing by @martialblog in https://github.com/NETWAYS/check_mumble_ping/pull/1

Full Changelog: https://github.com/NETWAYS/check_mumble_ping/commits/v1.0.0