Gather stats abour run/failed/succeeded examples

[lucaspiller]

trafficstars

Just found this, looks good. Fixes #11.

Need to check through code more thoroughly and add specs.

[benmmurphy]

should try and push this into a listener and not in the main file if possible. we pass listener state around but since we don't have any listeners that rely on state being preserved i'm not sure if it actually works or not.