Fixing some of the rough spots around fetching utilization metrics#2

Merged

robscott merged 2 commits intomasterfrom rs/metrics-fixes

Feb 5, 2019

+24-14

Commits on Feb 5, 2019

only attempting to fetch utilization numbers if requested, nicer error messages, related readme updates, hopefully fixes #1
robscott
committed
more helpful metrics-server error messages
robscott
committed