More realistic/reasonable default delays
1000 seconds seems like a lot!
I think 1 second would be a more reasonable default.
I realise that the delays can be turned off entirely, but for my purposes (testing a node.js dynamodb client) I actually prefer them to be there - it just took me a while to realise that the default was waaaaaaaay longer than what typically occurs on DynamoDB proper. And in keeping with the aims of this library, I think it should support a more realistic number out of the box.