0.main.js引入animate.css
1.给router-view标签外层加上transition标签，并且router-view标签要改成<router-view></router-view>
2.在transition标签加上两个类：enter-active-class 和 leave-active-class
<transition enter-active-class="animated bounce" leave-active-class="animated hinge"> <router-view></router-view> </transition>
