Release GCompris 3.1

Today we are releasing GCompris version 3.1.

As we noticed that version 3.0 contained a critical bug in the new "Comparator" activity, we decided to quickly ship this 3.1 maintenance release to fix the issue.

It also contains some little translation update.

You can find packages of this new version for GNU/Linux, Windows, Raspberry Pi and macOS on the download page. This update will be available soon in the Android Play store, the F-Droid repository and the Windows store.

Thank you all,
Timothée & Johnny