[ONOS-4016] Add Region codec with unit test for Region REST API

Change-Id: Ib7d6daa3adf8b23bea681e7bd3ef64839be65d13
diff --git a/core/common/src/main/java/org/onosproject/codec/impl/CodecManager.java b/core/common/src/main/java/org/onosproject/codec/impl/CodecManager.java
index de74801..5bea2d3 100644
--- a/core/common/src/main/java/org/onosproject/codec/impl/CodecManager.java
+++ b/core/common/src/main/java/org/onosproject/codec/impl/CodecManager.java
@@ -58,6 +58,7 @@
 import org.onosproject.net.meter.Band;
 import org.onosproject.net.meter.Meter;
 import org.onosproject.net.meter.MeterRequest;
+import org.onosproject.net.region.Region;
 import org.onosproject.net.statistic.Load;
 import org.onosproject.net.topology.Topology;
 import org.onosproject.net.topology.TopologyCluster;
@@ -121,6 +122,7 @@
         registerCodec(NextObjective.class, new NextObjectiveCodec());
         registerCodec(McastRoute.class, new McastRouteCodec());
         registerCodec(DeviceKey.class, new DeviceKeyCodec());
+        registerCodec(Region.class, new RegionCodec());
         log.info("Started");
     }