Check Gemfile.lock into version control

See http://yehudakatz.com/2010/12/16/clarifying-the-roles-of-the-gemspec-and-gemfile/
Adding Rspec as a dependency
Switching the gem sources to https://rubygems.org

The source :gemcutter is deprecated because HTTP requests are insecure.
Initialising Rspec.

`bundle exec rspec --init`
Load Capybara with Rspec.
Added an Rspec port of the existing Cucumber feature file.
Remove unnecessary sleep.

See Capybara.default_wait_time https://github.com/jnicklas/capybara#asynchronous-javascript-ajax-and-friends
Adding an .rspec file to set explicit output formatting.
Merge pull request #1 from liquid/rspec-version

Added an Rspec version of the example test