I wanted to add a quick note on how to create a gemfile. In the simplest terms, use bundler. It makes creating a Gem very easy!
bundle gem <gemname>
$ bundle gem sudokusolver
Initializating git repo in /Users/jimnanney/code/ruby/sudokusolver
I create a separate gemset for each project.
rvm rvmrc create 2.0.0@sudokusolver --ruby-version
Adding RSpec is simple as well. Just add the following to the .gemspec and run bundle.
spec.add_development_dependency "rspec", "~>2.1"
Follow this with rpsec –init and your spec directory and .spec_helper and .rspec will be created for you.
You’ll also want to add the following to your Rakefile to create the RSpec tasks:
task :default => :spec