compatible with ruby 1.8.7, information abould failed scenarios
Minor refactoring
Adding open3_backport when using Ruby 1.8
RUBY_VERSION global var is a string
Remove open3_backport from dependencies
Updating travis config
Adding open3_backport as development dependency since native extensions are not installed during tests
Merge pull request #3 from jeffersongirao/ruby18

add ruby 1.8.7 compatibility