Add initial support to load port map from olt configuration if present.
Run the test case under olt config environment as appropriate.
Change the subscriberTest to load and use olt configuration if present before
falling back to default configuration from the auto-generated subscriber port map.
diff --git a/src/test/setup/olt_config.json b/src/test/setup/olt_config.json
new file mode 100644
index 0000000..83e2b06
--- /dev/null
+++ b/src/test/setup/olt_config.json
@@ -0,0 +1,2 @@
+{ "olt" : false , "ports" : { "tx" : "veth2", "rx" : "veth0" } }
+