Modify references from PhantomJS to TrifleJS.

Since TrifleJS is explicitly a port of PhantomJS to the .NET framework[1], it follows that we should reuse as much of the PhantomJS configuration as we can for Karma. In this light, it makes more sense to simply fork the Phantom config from the Karma folks and point to Trifle specific resources instead.

This way any changes from upstream and Phantom can be handled (relatively) painlessly.

[1] "The API is a coded as a port of PhantomJS." : http://triflejs.org/