Code review comment for lp:~jani/ubuntu-system-image/skip-gpg-verification

I'm finally getting a chance to review this! ;)

Thanks very much for your contribution. I'd like to see one more test to prove that --skip-gpg-verification actually works. The test would craft an update that has a broken signature, and would show that without this flag, the update fails. Then, the cli would be invoked again with the flag and the update would pass. Can you add such a test?

Other than that, it looks quite good. Thanks.