Add new tac file that uses config from mounted volume.

opennsa-docker.tac

+#!/usr/bin/env python # syntax highlightning
+
+# This is .tac file for running OpenNSA directly from the source directory
+# without installing OpenNSA. Handy for testing.
+# Run directly in the terminal with: twistd -ny opennsa.tac
+# Spawn deamon with twistd -y opennsa.tac
+
+
+from opennsa import setup
+
+# you can get debug and/or payload info in the log by setting one of the flags to true
+application = setup.createApplication('/opennsa-config/opennsa.conf', payload=False, debug=False)