Modifying the current tabview code to animate and slide from side to side.
Fixed failing tests for the new tabview code
Clean ups as per review
Merge branch 'develop' into huwshimi-sliding-tabs

Conflicts:
	app/templates/bundle.handlebars
Merge pull request #81 from hatched/huwshimi-sliding-tabs

This branch provides a drop-in replacement for the existing TabView widget with the difference being a horizontal animated transition between the tabs.

This is a new PR for Huw's sliding tabs branch (https://github.com/juju/juju-gui/pull/74)

I fixed the failing tests and rebased the 27 commits down to one.