Add bower.json: Configuration file for the Bower package manager

Hi!

Thanks for KnobKnob. I used it in a itagenten's [Flux140](https://github.com/itagenten/flux140) project, in which I used Yeoman and the Bower package management system. rockgobo made me aware that I missed updating my deps config flie to make installation easy for others. For that, I need KnobKnob as a Bower package. I took the liberty of adding that package to the Bower Registry. To complete that step and list dependencies, I added a bower.json file.

Here's the output of my adding KnobKnob to Bower:
```
> bower register knobknob https://github.com/martinaglv/KnobKnob
bower convert       Converted https://github.com/martinaglv/KnobKnob to git://github.com/martinaglv/KnobKnob.git
bower resolve       git://github.com/martinaglv/KnobKnob.git#*
bower checkout      knobknob#master
bower resolved      git://github.com/martinaglv/KnobKnob.git#master
[?] Registering a package will make it installable via the registry (https://bow[?] Registering a package will make it installable via the registry (https://bower.herokuapp.com), continue? Yes
bower register      git://github.com/martinaglv/KnobKnob.git

Package knobknob registered successfully!
All valid semver tags on git://github.com/martinaglv/KnobKnob.git will be available as versions.
To publish a new version, just release a valid semver tag.

Run bower info knobknob to list the available versions.
```

Cheers,

Florian