This commit consists of:
1) Parsing protobuf responses from Voltha into a dict which will also
   include the yang proto annotations
2) Converting a protobuf response into a yang-compatible XML format
3) Support for GET (no request params) for Voltha, VolthaInstance and VolthaInstances
4) Minor bug fixes
5) Testing done using the MG-Soft Netconf client

Change-Id: Ibb7f62a391e19b0240cc739919fccc689a316005
diff --git a/netconf/nc_rpc/ext/get_voltha.py b/netconf/nc_rpc/ext/get_voltha.py
index a083401..0c51e9a 100644
--- a/netconf/nc_rpc/ext/get_voltha.py
+++ b/netconf/nc_rpc/ext/get_voltha.py
@@ -28,10 +28,8 @@
 
 
 class GetVoltha(Rpc):
-    def __init__(self, rpc_request, rpc_method, voltha_method_ref, grpc_client,
-                 session):
-        super(GetVoltha, self).__init__(rpc_request, rpc_method, voltha_method_ref,
-                                        grpc_client, session)
+    def __init__(self, request, grpc_client, session):
+        super(GetVoltha, self).__init__(request, grpc_client, session)
         self._validate_parameters()
 
     @inlineCallbacks