[AWS | AutoScaling] Do not send Instances for update_auto_scaling_group
(Avoids 413 Request Entity Too Large for ASGs with lots of instances)
[AWS | Autoscaling] whitelist the options for update_auto_scaling_group
[AWS | Autoscaling] whitelist the options for create_auto_scaling_group
[AWS | Autoscaling] dry up expected options
[AWS | Autoscaling] correct whitelist for create_auto_scaling_group
[AWS | Autoscaling] ensure tests work in 1.8.7
Merge pull request #1874 from mikehale/asg-exclude-instances

[AWS | AutoScaling] Do not send Instances for update_auto_scaling_group