Code review comment for ~cjwatson/launchpad:ci-build-upload-make-spr

I'm not in favor of using `attrs` either.

I suggested to use named tuples because they can be automatically converted to 3.6 syntax with `pyupgrade` (https://github.com/asottile/pyupgrade#typingnamedtuple--typingtypeddict-py36-syntax) and left as is, or converted to `dataclass` with minimal manual work.