You can use the DOMUSTO server command-line tool to upgrade DOMUSTO server to the lastest version:
./domusto.js upgrade
First set the package source to the latest version and upgrade nodejs.
curl -sL https://deb.nodesource.com/setup_9.x | sudo -E bash -
sudo apt install nodejs
When updating nodejs after you installed DOMUSTO server. You need to remove the node_modules
folder, install the DOMUSTO depencencies and plugin dependencies again:
rm -rf node_modules && npm install && ./domusto.js plugin install-deps