axios 设置header

两种方式：
1：

 let token = localStorage.getItem('token')

 if (token) axios.defaults.headers.common['token'] = token;

 axios.get(this.baseUrl + '/home/guestbook/list')
...................

2：

let token = localStorage.getItem('token')                
 if(token){axios.defaults.headers.token = token; }