Code review comment for lp://staging/~xnox/ubuntu-cdimage/focal-oem

Tested locally that unittests pass, and that download completes:

===== Downloading live filesystem images =====
Mon Dec 23 10:23:26 UTC 2019
2019-12-23 10:29:20 URL:https://launchpadlibrarian.net/456858940/livecd.ubuntu.squashfs [2086760448/2086760448] -> "/home/xnox/canonical/ubuntu-cdimage/scratch/ubuntu/focal/daily-live/live/amd64.squashfs" [1]
No keys found; not signing images.
2019-12-23 10:29:22 URL:https://launchpadlibrarian.net/456858932/livecd.ubuntu.kernel-generic [11399928/11399928] -> "/home/xnox/canonical/ubuntu-cdimage/scratch/ubuntu/focal/daily-live/live/amd64.kernel-generic" [1]
2019-12-23 10:29:24 URL:https://launchpadlibrarian.net/456858933/livecd.ubuntu.kernel-oem [8359576/8359576] -> "/home/xnox/canonical/ubuntu-cdimage/scratch/ubuntu/focal/daily-live/live/amd64.kernel-oem" [1]
2019-12-23 10:29:39 URL:https://launchpadlibrarian.net/456858927/livecd.ubuntu.initrd-generic [86440094/86440094] -> "/home/xnox/canonical/ubuntu-cdimage/scratch/ubuntu/focal/daily-live/live/amd64.initrd-generic" [1]
2019-12-23 10:29:52 URL:https://launchpadlibrarian.net/456858930/livecd.ubuntu.initrd-oem [76189083/76189083] -> "/home/xnox/canonical/ubuntu-cdimage/scratch/ubuntu/focal/daily-live/live/amd64.initrd-oem" [1]