示例：
单选radio
<label ><input type="radio" value="0" v-model="branch">debug</label>
<label > <input type="radio" value="1" v-model="branch">release</label>
容易出错的
例子：绑定了两个model
<label ><input type="radio" name="name1" value="0" v-model="branch">debug</label>
<label > <input type="radio" name="name1" value="1" v-model="branch1">release</label>