Removed logic from our tests!

Changed each test to setup then asset to make it easier to work out what is being tested.

Trailing space removal.

This was an accidental commit.
Lint fix.

Whitespace removal.
Refactor variable names to make more sense.

Removed trailing spaces.

Lint fix.
Refactored single_stat.js to fix graph errors.

When 'change:selected' we should only work with the model that's emitted.

If we're not on a line (eg a part of the graph with no data the matrix emits an array) so we now have some logic to test for an array.
Previously it was doing [].get('something') which was throwing exceptions. We now test for that logic and pick the first model from that array.
Added tests for events on single_stat.

Covers the missing logic that was never tested.

Added tests for how we deal with arrays from matrix collections.
Added the ability to hover over the graph axis.

In trying to fix a bug I removed the ability to hover.

This addresses the issue.