David Runge authored
arch_release_promotion/files.py: Add `load_release_from_json_payload()` to read a JSON payload and return it as a Release instance. Add the `ProjectFiles` class to aid in the synchronization of promoted release types of a project by bundling all necessary functionality. The special factory method `ProjectFiles.sync()` allows the creation of a `ProjectFiles` instance and direct synchronization of the configured amount of release versions of the project. tests/test_files.py: Add tests for `load_release_from_json_payload()`. Add tests for `ProjectFiles` and all of its classmethods and instance methods.