railsbridge/curriculum — pull request #4 by nuclearsandwich (2011-11-19 16:12:11+00:00)
Title: Make sure the `pg` gem gets included in the Gemfile for Heroku.

When following the instructions step by step, Heroku is broken because
the `pg` gem is not installed. This commit adds a step for doing so in a
logical place and provides a brief introduction to the purpose of the
Gemfile.