Improve routeCacheFile test
Improve routeCacheFile test

Ensure that the cached routes file actually contains dispatchable
routes.

juliangut/Slim,dopesong/Slim,RealSelf/Slim,JoeBengalen/Slim,iinux/Slim,akrabat/Slim,slimphp/Slim,iinux/Slim,iinux/Slim,Sam-Burns/Slim,foxyantho/Slim