Test on both Ubuntu LTS and "rolling"

We currently us a 10 month old version of Ubuntu (18.10) in the CI test, which is neither the latest LTS (18.04.3) not the latest "rolling" (19.10).

We should update to the latest, but also make sure it works on LTS.

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information