Adding bower.json

Hi there,
To make it easier to have annyang as a dependency, I created the `bower.json` package file.
I noticed it #40 is open and it mentions version 0.3.0. This bower.json file states 0.2.0, the current version.

To register as a bower package, you need to have bower installed: `npm install bower -g`
And run: `bower register annyang https://github.com/TalAter/annyang.git`

Cheers!