add DescribeAutoScalingGroups action, use dedicated client (with to be
introduced Endpoint interface)
add --trusty flag for listing canonical images
add NewFromEnv api for hetzner
fix SignAwsRequest method (use correct sha algorithm)
NewFromEnv never panics, add Validate method instead
use dedicated error for cloudformation "no updates" scenarion
add Makefile
add UpdateImtem action for dynamo