Change maintainers from @beorn7 to @bwplotka/@kakkoyun (#873)
Change maintainers from @beorn7 to @bwplotka/@kakkoyun (#873)

Lazy consensus was already established among prometheus-team. This
change will be announced on prometheus-developers@ once it is merged.

Signed-off-by: beorn7 <91e32ae1d26bd312b370cf8378a5a83accca90a0@grafana.com>
m3db/prometheus_client_golang,prometheus/client_golang