This reverts a334425c.

The main reason is that now the workflow is inconsistent when using
spring.

When using spring `RAILS_ENV` is always set, so only one database is
created.

This means that in development `bin/rake db:create` and `bundle exec
rake db:create` have different results.

It also breaks the `bin/setup` script since `bin/rake db:setup
db:test:prepare` will fail.