Differences with [django-bunny-storage](https://github.com/willmeyers/django-bunny-storage):
- `listdir` was added
- `_open()` now returns a file-like object (and therefore `File.read()` does not raise an error)
- `get_created_time()` was added
- `get_modfied_time()` was added
- `size()` was added
- `url()` does not prepend `/media/` to file paths anymore
- Improved support for Django `4.x`