fix linting errors

lib/6to5/traversal/scope.js

@@ -10,7 +10,6 @@ var flatten  = require("lodash/array/flatten");
 var extend   = require("lodash/object/extend");
 var object   = require("../helpers/object");
 var each     = require("lodash/collection/each");
-var has      = require("lodash/object/has");
 var t        = require("../types");
 
 /**
@@ -163,7 +162,7 @@ Scope.prototype.rename = function (oldName, newName) {
       if (t.isReferencedIdentifier(node, parent) && node.name === oldName) {
         node.name = newName;
       } else if (t.isScope(node)) {
-        if (t.getBindingIdentifier(oldName) !== binding) {
+        if (scope.bindingIdentifierEquals(oldName, binding)) {
           this.skip();
         }
       }