Unit testing directives/services w/o a browser env

[iphands]

Hey guys, I want to start breaking down directive code into more testable/composible pieces, then write small focused unit tests that can execute quickly and are not dependant on a browser environment.

Opening this MR up so we can start discussing what we do and don't like about this kind of approach.

I will write some more examples and squash before the actual merge

[jharting]

@iphands IMHO this is a bit too complicated (functions to produce actual functions, passing $scope, ...). I think you can get the same outcome by using AngularJS' built-in tooling for mock injection and unit testing. See e.g. https://github.com/RedHatInsights/insights-frontend/blob/master/test/unit/components/maintenanceTable_spec.js#L78

We would likely still need to make changes to controllers to make them more easily testable however I expect these changes to be lighter.