Postgres define o usuário como superusor
ALTER USER myuser WITH SUPERUSER;
Classy Answer
ALTER USER myuser WITH SUPERUSER;sudo -u postgres createuser -s -i -d -r -l -w <<username>>
sudo -u postgres psql -c "ALTER ROLE <<username>> WITH PASSWORD '<<password>>';"
create USER <<username>>;
ALTER USER <<username>> WITH SUPERUSER;
ALTER USER <<username>> WITH PASSWORD '<<password>>';