Code review comment for ~ahasenack/ubuntu/+source/ubuntu-advantage-tools:disco-v18-update

Updated and pushed. There are other mentions of "PPA" elsewhere in the code (status messages, that kind of thing), but changing those is a bigger chunk of work as it also affects tests and UI. I would prefer to change that in a later version. The PPA change you noted in the help output was indeed an oversight and what I did is just a continuation of https://github.com/CanonicalLtd/ubuntu-advantage-script/pull/153, so that's OK to do here.

I also updated the README.md file regarding the CIS audit tool. No URL for it yet, though, so I'll just leave it mentioned.