Fix build on ruby 1.8.7

Author: Can Berk Güder and Tyler Schultz

spec/cli_spec.rb

@@ -392,7 +392,7 @@ def committer_email_of_last_commit
  def git_pair_commit
  run "echo #{rand(100)} > b"
  run 'git add b'
- run 'git pair-commit -m "Pair pare pear"', fail: true
+ run 'git pair-commit -m "Pair pare pear"', :fail => true
  end
  end
 end