No need to specify credentials as the client picks them up from environment variables, system properties
or IAM role. Aim is to allow the client to work using IAM roles when deployed inside AWS.

Create table now has :wait parameter which specifies that the call should not return until the table
is active and ready to be used.

Only create secondary indexes when some are specified, possibly change needed because of use of updated AWS SDK.

Updated to latest AWS Java SDK 1.6.5.