Sauce Integration 

Can someone review this, I haven't worked with `karma` before. Tests pass locally, but the sauce component is still untested.

Based the `karma.conf-sauce` file on [angularjs's karma sauce integration](https://github.com/angular/angular.js/blob/master/karma-shared.conf.js)

(BTW Sauce accounts are Jeremy's)
Can we also get compat mode tests in here? Would help spot bugs like #1621 earlier.