Removed footer tests, prepped for more changes

1. Footer tests don't apply here, it is included via directive, and is
thus unavailable to the gridTemplate.html DOM

2. Moved the grid instantiation code to a beforeEach(), so
AssignGridContainers tests can each run independently (eventually).
Moved to Chrome for karma unit testing

PhantomJS wasn't printing the failing test file or line number (i.e. stack
trace). Chrome does.
ngHeaderScroller had wrong expected width

Needed to be 417px but was 419px. 2px was removed at some point.
Adding test details to README
Removing e2e test specs as they're not defined yet