If ruby is segmentation faulting on Travis CI, try updating libxml
Ruby 1.9.3 on Travis CI now includes a RubyGems version greater than 2.0. This breaks Rails 2. Here’s how to fix it.
Poltergeist requires at least PhantomJS 1.7.0. Travis CI provides 1.6.1. Here’s how to bump your version of PhantomJS.