Fixes unit listing with test update.

* Call aggregate update when we add uncommitted units. The unit list and unit
  count update is dependent on this operation firing off.

* Update tests to ensure this is called.
Right but that's not done here, that's done in ghost-deployer-extension.js via the `addUnits` call so this is assuming that we make that call. By moving the aggregates update method (mentioned below) into the `addUnits` call it will update this appropriately every time it's needed.