### Do you want to: * ... drop Python 2 support (and make 3.7 the new minimum required version)? * ... migrate to pyproject.toml? (see PEP621) * ... add inplace type hints / annotations? (see PEP561) * ... migrate to `click` for the `srt_tools`? (all scripts can be grouped into subcommands like how `git` does) * ... use `attrs` for `Subtitle` class instead of hand-coding all dunder methods?