axios中为所有请求带上Token头

axios.post('signToken', {
  "NickName": "xxxx",
  "Password": "xxxx",
  "RequestSign": "B858C5EEE7FD4D37C635FB55841ACA59"
}).then(res => {
  axios.defaults.headers.common['Authorization'] = res.headers.authorization
  //实例化Vue
  new Vue({
    el: '#app',
    router,
    components: {
      App
    },
    template: '<App/>'
  })
})