Adding updated values for recurring autoscale operations

The latest documentation for auto scale groups (http://docs.aws.amazon.com/AutoScaling/latest/APIReference/API_PutScheduledUpdateGroupAction.html) has options for scaling out based upon a cron.  The values were not present by default, and this PR adds those variables to the autoscale __init__.py and schedule.py file.

Let me know if I need to change the format of any of this!