This introduces support for the resource metrics in the adapter.
The individual queries and window sizes are fully customizable via a new
config section. This uses just the generic machinery from
metrics-server to serve the API.
This updates the dependencies to Kube 1.11.3 to pull in a fix allowing
requestheader auth to be used without normal client auth (which makes
things work on clusters that don't enable client auth normally, like
EKS).