Update bower.json to reflect spec

just some little bower things...

* `"main"` [should never include minified files](https://github.com/bower/bower.json-spec#main-stringarray-of-strings)
* `bower.json` is always needed, it [can't be ignored](http://stackoverflow.com/a/17920572/414825)
* same goes for `README.md`, it [can't be ignored](https://github.com/bower/bower.json-spec#ignore-array-of-strings)