better model for mutually exclusive attributes about zookeeper-cookbook

[mwhooker]

Having switch logic in attributes probably would work fine.

The fact that we merged a commit which made IAM usage implicit based on the existence of an s3config file broke it.

[jakedavis]

We definitely need better logic around this. All of the current config was moved out as-is to the Exhibitor cookbook. Going to track in a similar issue there. This will be relevant to this cookbook as well though.

[jakedavis]

I think we're doing pretty good here.

[jakedavis]

Oh man, @mwhooker, WTF I thought you would still have collab on this. I am fixing that now.

[jakedavis]

Sorry man, should be fixed now. I added you to exhibitor too, same with @jeffbyrnes and @eherot.