too much "no pingable members" when running single-node cluster

[gl-works]

Thanks for make the awesome ringpop. But it constantly warning "no pingable members" when running a single-node cluster which is too much annoying. It should be better if lower log level to DEBUG.

WARN[0000] no pingable members                           local=gMac.local:5000
WARN[0000] no pingable members                           local=gMac.local:5000
WARN[0000] no pingable members                           local=gMac.local:5000
WARN[0002] no pingable members                           local=gMac.local:5000
...