Make logline clearer as to whether hosts are up or down in EurekaHostsSupplier

[smukil]

dyno/dyno-contrib/src/main/java/com/netflix/dyno/contrib/EurekaHostsSupplier.java

Line 123 in 786b6b2

Logger.info("Dyno found hosts from eureka - num hosts: " + hosts.size());

Something like:
"Dyno found hosts from eureka - num hosts: | Num up: <num_up> | Num down: <num_down>"