Gotcha: Initialising RSpec in a rails project

I use RSpec for doing TDD, and the rspec-rails gem for integration in Rails projects. On initialising RSpec for SOLDN2, with rspec init it generated the following spec helper (comments removed):

Getting to grips with postgres

So, having generated my Rails app and selected postgres as the development database, I’m now faced with getting the damn thing running. On a Eurostar train (under the English channel) i.e. with no internet.