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

> OK, I've converted this to a plain class with `__init__` boilerplate as you suggest. How's this?

This looks great

PyCharm reports two issues:

1. The signature of `CIBuildUploadJob.create()` doesn't match the base`ArchiveJobDerived.create()` - this may be ok
2. `scanned` argument in `_uploadSources` should probably be a `Sequence` rather than an `Iterable` because you're doing `scanned[0]` there