add stubs for NTCP

lib/transport/ntcp/session.go

@@ -0,0 +1,6 @@
+package ntcp
+
+// Session implements TransportSession
+// An established transport session
+type Session struct {
+}

lib/transport/ntcp/transport.go

@@ -0,0 +1,5 @@
+package ntcp
+
+// Transport is an ntcp transport implementing transport.Transport interface
+type Transport struct {
+}