Remove 'client' references because the property has been removed from AWS SDK

From the official release notes here:  http://docs.aws.amazon.com/AWSJavaScriptSDK/latest/file.UPGRADING.html#4__Dropped__Client_Property and made official in commit aws/aws-sdk-js@a6ee7496a330183a75e81621d817c8167c7c1404 the .client property has been removed.

This change moves the codebase to the non-deprecated API