Update the version of metrics-server shipped with cf-for-k8s

[james-pollard-leapyear]

I noticed in https://github.com/cloudfoundry/cf-for-k8s/blob/develop/config/metrics/add-metrics-server-components.yml that the yaml is still from v0.3.6 even though many versions have since come out.

https://github.com/kubernetes-sigs/metrics-server/releases

PS Hi y'all! I copy bits and pieces of ytt code from you every couple of weeks. So... thank you!

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this:

https://www.pivotaltracker.com/story/show/178441447

The labels on this github issue will be updated when the story is started.

[davewalter]

Hi James. Good catch. We should automate this!