Minor reformatting.
Ask all questions up front. Use constants instead of variables for options.
Use copy_file() instead of my custom pull_file().
Change the order we ask questions, so we don't have to redefine ACTION_MAILER.
Don't need to run haml --rails for modern versions of HAML gem.
Use built-in actions instead of my own.
Create and use after_bundle().

This allows running bundle install a single time, and deferring running
certain things until after all the gems have been installed.