Rework loadreport to incorporate new PhantomJS 2 performance APIs

[wesleyhales]

PhantomJS 2 provides the following properties from the performance/timing apis:
https://gist.github.com/wesleyhales/b23f6d7dae5ef66ac630

I want to rework this project to use the new metrics. I'm also open to suggestions on refactoring the project completely :) if you're interested @maboiteaspam @jeromecovington @clakech and others

[wesleyhales]

The new branch is here:
https://github.com/wesleyhales/loadreport/tree/2.0.0