TL;DR
Install Postgres 9.6, and then:
sudo pg_dropcluster 9.6 main --stop
sudo pg_upgradecluster 9.5 main
sudo pg_dropcluster 9.5 main
Set db path for pg_upgradecluster:
TL;DR
Install Postgres 9.6, and then:
sudo pg_dropcluster 9.6 main --stop
sudo pg_upgradecluster 9.5 main
sudo pg_dropcluster 9.5 main
Set db path for pg_upgradecluster: