Fail autoscale deploy if you do not have enough capacity

Autoscaling deploy will now fail if the Max Size of the group is not enough to double the desired instances.

#85 

Rather than build it into DoubleSize I put it in early so it fails before we turn off autoscaling and such.

![max_size](https://f.cloud.github.com/assets/76709/397119/2f4fbdf0-a837-11e2-9149-586c87e11610.png)