如何正确使用vue-materials标签路由器和vue-router？

npm install vue vue-router

import Vue from 'vue'
import VueRouter from 'vue-router'
import VueMaterial from 'vue-material'
import 'vue-material/dist/vue-material.css'

Vue.use(VueRouter)
Vue.use(VueMaterial)

import Vue from 'vue'
import VueRouter from 'vue-router'
import Home from './components/Home.vue'
import About from './components/About.vue'

Vue.use(VueRouter)

const routes = [
  { path: '/', component: Home },
  { path: '/about', component: About }
]

const router = new VueRouter({
  routes
})

export default router

import Vue from 'vue'
import App from './App.vue'
import router from './router'

new Vue({
  router,
  render: h => h(App)
}).$mount('#app')

<template>
  <div>
    <md-toolbar>
      <md-button @click="$router.push('/')">Home</md-button>
      <md-button @click="$router.push('/about')">About</md-button>
    </md-toolbar>
    <router-view></router-view>
  </div>
</template>