Example swf initialization code errors

[edenhochbaum]

On the swf-basics page, we see:

AmazonSimpleWorkflowClient swf = AmazonSimpleWorkflowClientBuilder.defaultClient();

This won't compile, since AmazonSimpleWorkflowClientBuilder.defaultClient() is declared to return an instance of AmazonSimpleWorkflow, which isn't compile-time guaranteed to be an AmazonSimpleWorkflowClient instance.