GNOME Software upgrade image

[Ryan Lerch]

IIRC, the background image (the default Fedora background for a release) we
use as the background for the upgrading slide in GNOME Software was not
updated properly until after the F26 Release.

Is there anyway we can check that this is showing the correct background
before release? If i follow the directions here on the magazine [1], it
still shows the flat blue fallback background.

cheers,
ryanlerch

[1] https://fedoramagazine.org/upgrade-fedora-workstation-fedora-27-beta/