Update travis to validate Ruby v1.9.3-p484

Need to test against 1.9.3-p484 for PE support

removed the sort method from defaultGroup

removed the .sort method from the defaultGroup configurations stanza,
@defaultGroup gets sorted in the manifest, *and* is a string object.

https://github.com/huit/puppet-splunk/blob/09d522bb29ccd6449471efb47e1ab9df68577c35/templates/opt/splunk/etc/system/local/outputs.conf.erb#L4

This worked in Ruby 1.8.7 but blows up with 1.9.3