Installed software:
Redmine 3.2.1 Ruby 2.2 (Rails 4.2) PostgreSQL 9.5
In this release postgresql has open port for the host machine. You can access to the postgresql with the command:
$ psql -h 127.0.0.1 -p 5432 -U postgres
PostgreSQL password is: changeme
If you can't wish access to the postgresql instance in the vagrant host you can disable port forwarding in the Vagrant file.
Redmine 3.0.0 + Ruby 2.2 (Rails 4.2) + PostgreSQL 9.4
Redmine 2.6.1 + Ruby 2.1 (Rails 3.2) + PostgreSQL 9.4