Fix bug if no value is supplied.

lib/networks.js

@@ -75,7 +75,7 @@ function addNetwork(data) {
   });
 
   _.each(_.values(network), function(value) {
-    if (!_.isObject(value)) {
+    if (value && !_.isObject(value)) {
       networkMaps[value] = network;
     }
   });