auto import css

added test and functionality for auto import

updated cli to handle this functionality as well

PLEASE NOTE:  you must add the following to atomify-js at line 62 in the node_modules folder!!! 
```javascript
  b.on('package', function(pkg){
    emitter.emit('package', pkg)
  })
```

breaks no tests (that werent already broken) ... let me know what you think or if you need more in depth examples!

yes this adds a bit to your atomify code, it isnt very pretty, but it can be optimized or made prettier or whatever... just would LOVE to have this functionality!!!

in a nutshell it listens for package events from browserify, and then looks for each packages style property or index.css which (if existing) are compiled as @imports into a temporary css file, then runs that temp file through atomify-css and deletes it after bundling.  this could be more elegant by accumulating the @imports as a string and run them directly into atomify-css but it doesnt appear this is possible, it requires a file ATM