first, here are my versions:
Greg-Nowickis-MacBook-Pro:sample_app Greg_Nowicki$ ruby -v ruby 2.0.0p451 (2014-02-24 revision 45167) [x86_64-darwin13.1.0] Greg
Try using a different version of rspec by replacing the beta version with this version in your Gemfile: gem 'rspec-rails', '>= 2.14'
gem 'rspec-rails', '>= 2.14'
EDIT: Have you run bundle install and rails generate rspec:install before trying to run rspec?
bundle install
rails generate rspec:install