Fixing gp.recipe.phantomjs to honor relative paths

* modifying the flow to generate relative paths if the "relative-paths" option is set to true
* adding a couple unit tests
* adding travis.yml
making a commit to kick travis off
added sorting for consistent results
Merge pull request #15 from toumorokoshi/relative

Adding fix to allow gp.recipe.phantomjs to honor relative-paths buildout option