cg1.4xlarge instances have 2 gpus

Hey there, according to the [aws docs](http://aws.amazon.com/ec2/instance-types/instance-details/), cg1.4xlarge instances actually have 2 gpus.

"CG1 instances are backed by 2 x Intel Xeon X5570, quad-core with hyperthread plus 2 NVIDIA Tesla M2050 GPUs"