Add dump command

Change-Id: If38d01ebb8788090f91a76daf6b7fc9add0320b7
diff --git a/src/yang_operations.hpp b/src/yang_operations.hpp
index c8dc1a0..fdb9c2e 100644
--- a/src/yang_operations.hpp
+++ b/src/yang_operations.hpp
@@ -30,3 +30,8 @@
     Running,
     Startup
 };
+
+enum class DataFormat {
+    Xml,
+    Json
+};