building scheduler should set kubernetes-internal version info

[sharnoff]

k8s.io/component-base/version/version.go defines the way that K8s components retrieve version information. tl;dr: there's some more variables we should set at build-time with ldflags, because the scheduler prints them on startup.

All their constants are pretty reasonable IMO; we might want to switch to either (a) using them directly [may interfere with #54] or (b) mirror them and duplicate the ldflags args just for the scheduler. Or, we could separately extract some information about which commit of the K8s repo we're using, and go from there — there's multiple options.