feat(driver): add basic chrome.storage.local driver

I've written a basic driver for using chrome.storage.local inside Chrome Packaged Apps. It works pretty well for my application but it's kind of hacky in places. 

Just putting it here so that others can try it / find issues and help me in writing tests and making this good enough for inclusion.

requested in #43 

chrome storage API : https://developer.chrome.com/extensions/storage