Adding tests for meter service.

Change-Id: Ic220fdaa89b421661019f1a6ef23c7b02eef127c
diff --git a/core/api/src/main/java/org/onosproject/net/meter/MeterContext.java b/core/api/src/main/java/org/onosproject/net/meter/MeterContext.java
index 005c41c..574bdca 100644
--- a/core/api/src/main/java/org/onosproject/net/meter/MeterContext.java
+++ b/core/api/src/main/java/org/onosproject/net/meter/MeterContext.java
@@ -26,7 +26,7 @@
      *
      * @param op a meter
      */
-    default void onSuccess(Meter op) {}
+    default void onSuccess(MeterRequest op) {}
 
     /**
      * Invoked when error is encountered while installing a meter.
@@ -34,5 +34,5 @@
      * @param op a meter
      * @param reason the reason why it failed
      */
-    default void onError(Meter op, MeterFailReason reason) {}
+    default void onError(MeterRequest op, MeterFailReason reason) {}
 }