The script needs a postgres user with username postgres and password postgres.
sudo apt-get install postgresql postgresql-contrib
sudo -u postgres psql postgres
\password postgres
By using PgAdmin III to show the postgres data, extra setup is needed.
sudo gedit /etc/postgresql/9.5/main/pg_hba.conf
and change the line
# Database administrative login by Unix domain socket
local all postgres peer
to (remote connections to the database are possible)
# Database administrative login by Unix domain socket
local all postgres md5