Update to Fedora 31

Fedora 31 is out for a while now, it's definitely stable enough to be the new base image.

Update to Fedora 31
38435429 · Sheogorath · c28a3b4e · 38435429
Verified Commit 38435429 authored 5 years ago by Sheogorath
--- a/Dockerfile
+++ b/Dockerfile
-FROM fedora:30
+FROM fedora:31

 COPY resources/storage.conf /etc/containers/