Added bower manifest to enable an official kube package to added to the bower repository.

Adding the Bower manifest to the official repository would mean that when you push an update, everybody who has Kube specified as a dependency in their project using Bower would get the update. At the moment there are a few bower packages of Kube which just point to outdated forks of Kube. 

The only maintenance would be bumping the version number in the bower.json file when a new version is released.