Fix test_clean_checkout_should_perform_git_clean not reflecting changes (and added comment to explain why those arguments where chosen)
Update travis to check only 1.8.7 and 1.9.3
Another attempt to workaround 1.9.3-p484 ruby / debugger gem versions issue
Update rake version to try and work around 1.9.3 rake version issue
Merge branch 'fix_git_clean_test' into rubyruy_master