Ubuntu 20 permissions error on last version

[dmitrykorikov]

I did testing multiple times
Ubuntu 18 install does not have this issue
Ubuntu 20 have this issue - Backend status: Connection refused

Ways to resolve:
docker exec -it cattr sh
cd backend
chmod 777 storage/ -R

[vermorag]

We haven't updated docker containre for a while. For now we are working on 4.0 release with new containers system. You can try to use it right now, or wait for a while until public release. You can find more info in #30