[PureOS] New PureOS images are ready for testing! (2020-07-18)

[Matthias Klumpp]

Hi!
We have new images ready for testing for both PureOS 9 (Amber) and the
Byzantium development version.

For the former, please give feedback on the updated images on their
tracking bug: https://tracker.pureos.net/T919

The Byzantium development images were also generated per-month as
usual and can be found at https://downloads.pureos.net/byzantium/ for
testing.

Cheers,
    Matthias