[ONOS-4127] Backup metric service to ganglia monitoring server

- Initial implementation of metric service reporter
- Unit test for metric service reporter
- Bump up metric lib from 3.1.0 to 3.1.2

Change-Id: Ia178df759d671dfc15cffaacb09d5279ad3d9ad8
diff --git a/utils/misc/src/test/java/org/onlab/metrics/MetricsServiceAdapter.java b/utils/misc/src/test/java/org/onlab/metrics/MetricsServiceAdapter.java
index 9593feb..59e6116 100644
--- a/utils/misc/src/test/java/org/onlab/metrics/MetricsServiceAdapter.java
+++ b/utils/misc/src/test/java/org/onlab/metrics/MetricsServiceAdapter.java
@@ -19,6 +19,7 @@
 import com.codahale.metrics.Counter;
 import com.codahale.metrics.Histogram;
 import com.codahale.metrics.Meter;
+import com.codahale.metrics.MetricRegistry;
 import com.codahale.metrics.Timer;
 import com.codahale.metrics.Gauge;
 import com.codahale.metrics.Metric;
@@ -39,6 +40,11 @@
     }
 
     @Override
+    public MetricRegistry getMetricRegistry() {
+        return null;
+    }
+
+    @Override
     public Counter createCounter(MetricsComponent component,
                                  MetricsFeature feature, String metricName) {
         return null;