Also, one idea I had was to setup a MemoryAdapter for the filesystem for testing purposes as outlined here:
http://flysystem.thephpleague.com/adapter/memory/ and http://laravel.com/docs/5.0/filesystem#custom-filesystems
However my Codeception tests error with:
[BadMethodCallException] Call to undefined method League\Flysystem\Filesystem::createMemoryDriver
If anyone knows why this might be and how I can resolve it that might be a workable solution for me...