Add Rubinius to .travis, required gems to Gemfile
Convert specs to RSpec 3.0.x syntax
Merge pull request #6 from petergoldstein/feature/convert_to_rspec_3_0_syntax

Convert specs to RSpec 3.0.x syntax
Merge pull request #5 from petergoldstein/feature/add_rbx

Add Rubinius to .travis, required gems to Gemfile