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/constants.py b/netconf/constants.py
index 7a503bc..e59a73e 100644
--- a/netconf/constants.py
+++ b/netconf/constants.py
@@ -54,6 +54,7 @@
     # Netconf namespaces
 	NETCONF_BASE_10 = "urn:ietf:params:netconf:base:1.0"
 	NETCONF_BASE_11 = "urn:ietf:params:netconf:base:1.1"
+	NETCONF_MONITORING = "urn:ietf:params:xml:ns:yang:ietf-netconf-monitoring"
 
 	# XML
 	XML_HEADER = """<?xml version="1.0" encoding="utf-8"?>"""