Accept olt_config file as a separate argument to cord-tester or to manifest.
Change all tests to use OLT_CONFIG_FILE environment as appropriate.
Add a manifest file for voltha scenario that can test AAA/TLS with voltha and access side ONOS.

Change-Id: I6af70cd38d9b14187790dea7011839b8ba614432
diff --git a/src/test/vsg/vsgTest.py b/src/test/vsg/vsgTest.py
index 2c1c05d..919a5ae 100644
--- a/src/test/vsg/vsgTest.py
+++ b/src/test/vsg/vsgTest.py
@@ -43,7 +43,7 @@
     head_node = os.getenv('HEAD_NODE', 'prod')
     HEAD_NODE = head_node + '.cord.lab' if len(head_node.split('.')) == 1 else head_node
     test_path = os.path.dirname(os.path.realpath(__file__))
-    olt_conf_file = os.path.join(test_path, '..', 'setup/olt_config.json')
+    olt_conf_file = os.getenv('OLT_CONFIG_FILE', os.path.join(test_path, '..', 'setup/olt_config.json'))
     restApiXos =  None
     subscriber_account_num = 200
     subscriber_s_tag = 304