Nothing terribly exciting here.
Alexs-MacBook-Air:sudoku alex$ ruby --version
ruby 2.2.1p85 (2015-02-26 revision 49769) [x86_64-darwin14]
Alexs-MacBook-Air:sudoku alex$ rspec --version
3.2.0
To run the tests:
Alexs-MacBook-Air:sudoku alex$ rspec spec/sudoku_spec.rb
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Finished in 0.01971 seconds (files took 0.22057 seconds to load)
39 examples, 0 failures