This needs to be in bower

I noticed that this wasn't in bower,  so I created a bower.json file, pointing to a new release tag (v0.2.1). 

If everything looks good, create a new release from the new tag, and then 

`bower register ng-focus-on https://github.com/goodeggs/ng-focus-on`

And ng-focus will be available via bower! Yay!

http://bower.io/#registering-packages