0.2.0

• Add software tests to CI/GHA
• Naming things: Add racker command with racker {pull,run} subcommands
• Improve subprocess stdout/stderr redirection and error handling
• Activate full umoci-unpacked images
• Add test case for postroj pkgprobe
• Improve image subsystem to acquire arbitrary Docker filesystem images
• Add operating system support for SLES 15, SLES BCI, RHEL, CentOS 9
• Add operating system support for RHEL UBI's "minimal" flavors
• Add custom exception objects
• Add more test cases to raise code coverage to >75%
• Refactoring: Bundle systemd-nspawn/machinectl to postroj.backend.nspawn
• Refactoring: Move code from setup_ubuntu to generic acquire_from_http

Full Changelog: 0.1.0...0.2.0