Decider Example needs to be updated for maxPageSize

[sukrit007]

As per AWS docs, maxPageSize can take a max value of 100.
http://docs.aws.amazon.com/AWSJavaScriptSDK/latest/frames.html

The example : https://github.com/neyric/aws-swf#creating-a-decider uses a maximum value of 500 and needs to be changed.