Added JSON for role command.
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/GossipDeviceStore.java b/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/GossipDeviceStore.java
index 6fbc034..ca88c66 100644
--- a/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/GossipDeviceStore.java
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/GossipDeviceStore.java
@@ -701,7 +701,7 @@
     public synchronized DeviceEvent removeDevice(DeviceId deviceId) {
         final NodeId master = mastershipService.getMasterFor(deviceId);
         if (!clusterService.getLocalNode().id().equals(master)) {
-            log.info("remove Device {} requested on non master node", deviceId);
+            log.info("Removal of device {} requested on non master node", deviceId);
             // FIXME silently ignoring. Should be forwarding or broadcasting to
             // master.
             return null;
@@ -778,7 +778,7 @@
     private Device composeDevice(DeviceId deviceId,
             Map<ProviderId, DeviceDescriptions> providerDescs) {
 
-        checkArgument(!providerDescs.isEmpty(), "No Device descriptions supplied");
+        checkArgument(!providerDescs.isEmpty(), "No device descriptions supplied");
 
         ProviderId primary = pickPrimaryPID(providerDescs);