Return :billing-mode :provisioned when BillingModeSummary is nil

[joelittlejohn]

The tests have started failing here although there have been no changes to the code. I think DynamoDB Local has changed behaviour (and since clj-dynamodb-local just downloads the latest, we're exposed to this kind of change).

It appears that a table set to provisioned billing mode can return a nil billing more summary. Since provisioned is the default, I suppose this is reasonable. I found reports on other projects that indicate people have seen real dynamo tables sometimes behave in this way, so I think it's something that we should accommodate rather than just update the test.

[kipz]

I was able to recreate the failure locally on master by removing the dynamodb-local cache directory which forces the update mentioned above:

rm -rf  ~/.clj-dynamodb-local/