Add support for configuring wan interface in olt config (olt_config.json)
If a wan interface is specified, then configure the test container
uplink port to use the wan interface on the host

Change-Id: I7e7462f829148a022feccac34404d38f0d2f7ca8
diff --git a/src/test/utils/OltConfig.py b/src/test/utils/OltConfig.py
index b1a3387..f3450a2 100644
--- a/src/test/utils/OltConfig.py
+++ b/src/test/utils/OltConfig.py
@@ -47,6 +47,9 @@
                     port_map['ports'].append('veth{}'.format(port))
             port_num = 1
             port_map['uplink'] = int(self.olt_conf['uplink'])
+            port_map['wan'] = None
+            if self.olt_conf.has_key('wan'):
+                port_map['wan'] = self.olt_conf['wan']
             port_list = []
             ##build the port map and inverse port map
             for port in port_map['ports']: