Adding `bower install` compatibility

Adding a `bower.json` file so we're able to install the repo via `bower install --save https://github.com/darsain/motio`.

I have noticed a small bug where the `bower.json` file doesn't get copied into the `bower_components/motio` directory after running the above `install`. No idea why this happens.

If you want to publish this to bower's public repo, run:

`bower register motio git://github.com/darasin/motio.git`

This is just my 2c.. Let me know what you think.

w