problem using test_delete_dataset and test_iter_dataset in CheckEngine

[nathanfranklin]

test_delete_dataset uses ds.name after ds has been deleted. It also remove datasets while iterating over the datasets.

test_iter_dataset assumes that iter_dataset returns the datasets in the order that they were added.

[nathanfranklin]

Closed by #220

[tuopuu]

I'll reopen this issue, because test_delete_dataset still references the proxy object and therefore the object is not deleted. See my previous line comment.

[nathanfranklin]

@tuopuu , we can close this again, right?

[tuopuu]

Yes, we can close this.