Keep nodeShapes in the same order as nodeTypes in the provisioners
Keep nodeShapes in the same order as nodeTypes in the provisioners

The ClusterScaler relied on provisioner.nodeShapes to be in a
particular order (to avoid having to parse out the nodeShapes
itself). But AWS and GCE provisioners both put non-preemptable
instances first in the list.

BD2KGenomics/slugflow,BD2KGenomics/slugflow