nodes and services in maintenance can cause excessive logging

When a cloud environment has nodes and/or services in maintenance then
fabio can generate excessive logging every time the routing table is
generated. Since these messages can be useful they remain in the code
but are being logged as DEBUG which after merging #366 is no longer
logged by default.

Fixes #367

registry/consul/passing.go

@@ -27,15 +27,15 @@ func passingServices(checks []*api.HealthCheck, status []string) []*api.HealthCh
 		// node and the service are not in maintenance mode.
 		for _, c := range checks {
 			if c.CheckID == "serfHealth" && c.Node == svc.Node && c.Status == "critical" {
-				log.Printf("[INFO] consul: Skipping service %q since agent on node %q is down: %s", svc.ServiceID, svc.Node, c.Output)
+				log.Printf("[DEBUG] consul: Skipping service %q since agent on node %q is down: %s", svc.ServiceID, svc.Node, c.Output)
 				goto skip
 			}
 			if c.CheckID == "_node_maintenance" && c.Node == svc.Node {
-				log.Printf("[INFO] consul: Skipping service %q since node %q is in maintenance mode: %s", svc.ServiceID, svc.Node, c.Output)
+				log.Printf("[DEBUG] consul: Skipping service %q since node %q is in maintenance mode: %s", svc.ServiceID, svc.Node, c.Output)
 				goto skip
 			}
 			if c.CheckID == "_service_maintenance:"+svc.ServiceID && c.Status == "critical" {
-				log.Printf("[INFO] consul: Skipping service %q since it is in maintenance mode: %s", svc.ServiceID, c.Output)
+				log.Printf("[DEBUG] consul: Skipping service %q since it is in maintenance mode: %s", svc.ServiceID, c.Output)
 				goto skip
 			}
 		}