VUE Router 问题 修改路由组建数据 不会自动渲染DOM

[Su_hibl]

<div id="app">
<router-link to="/user">首页</router-link>
<router-view></router-view>
</div>

<template id="t">
<ul>
<li v-for="(u,i) int users" v-text="u.name"></li>
</ul>
</template>

<script type="text/javascript">

var cmpUser={
template:'#t',
data:function(){
return {users:[{id:0,name:'lisi'}]}
},
created:function(){
this.users.push({id:1,name:'zhangsan'}); //只会 显示 users[0], 为什么不会自动渲染DOM
//this.$set('users',this.users); // 无效果
}

};
var router=new VueRouter({
routes:[
{path:'user',
component:cmpUser
}]
});


var vue=new Vue({el:'#app',router:router});

</script>