psql

$ sudo apt-get install postgresql postgresql-contrib
$ sudo -i -u postgres
$ psql
$ create role ubuntu;
$ alter role ubuntu with superuser;
$ alter role ubuntu with createdb;
$ alter role ubuntu with login;
$ \q
$ exit
$ sudo vim /etc/postgresql/9.5/main/pg_hba.conf

(In pg_hba.conf, find the rows labeled IPv4 and IPv6, and change 'md5' to 'trust')

$ sudo systemctl restart postgresql
$ psql -f schema.sql ubuntu