walkable.BFS的bug修复

Author: icefox0801

lib/component/Tree.js

@@ -31,13 +31,10 @@ var walkable = {
       }));
 
       if (children.length) {
-        var initialValue = {};
-        initialValue[walkable.childrenName] = [];
         var grandChildren = children.reduce(function (a, b) {
-          var subAChildren = a[walkable.childrenName];
           var subBChildren = b[walkable.childrenName];
-          return subAChildren.concat(subBChildren);
-        }, initialValue);
+          return a.concat(subBChildren);
+        }, []);
 
         if (grandChildren.length) {
           iterate(grandChildren);