In the development database, you'll use good practices like a custom schema and user, with reduced privileges.
For the test environment database, we'll keep things simpler. The postgres superuser is used along with the public schema. This configuration is also used for Circle CI.
From the Rideshare directory, run:
sh db/setup_test_database.sh, which sets uprideshare_testbin/rails test
Refer to .circleci/config.yml for the Circle CI config.
You should now have a test database, and tests should have passed.