For anyone interesting in upgrading their linux wallet to 1.3.0, I found an easy step-by-step courtesy of Crypto Sharks:
polis-cli stop
cd
wget https://github.com/polispay/polis/releases/download/v1.3.0/poliscore-1.3.0-x86_64-linux-gnu.tar.gz
tar -xvf poliscore-1.3.0-x86_64-linux-gnu.tar.gz
rm poliscore-1.3.0-x86_64-linux-gnu.tar.gz
cp poliscore-1.3.0/bin/polis{d,-cli} /usr/local/bin
polisd &
watch polis-cli getinfo
Should read "version": 1030000
Lifted from their video description at
https://www.youtube.com/watch?v=cZ__CyxtbCI