Postgres user has SUPERUSER

[jbinto]

The postgresql user bikeways_staging (et al) has SUPERUSER privilege. This is necessary to create the PostGIS extension.

This violates least privilege. We could fix this using the approach suggested in GeoRails:

You'll set up two users in the database. One is the normal database user that your Rails app will connect as. The other needs to be a superuser, and is used to create the databases initially (i.e. using rake db:create). Creating a PostGIS database requires superuser privileges unless you set up a special template for it, and for simplicity, we won't do that right now.

Curious about the template hint there. Not sure exactly what it means, but perhaps we could create a PostGIS template in the Ansible playbook.