路由守卫简单逻辑
router.beforeEach((to,from,next) => {
let token = localStorage.getItem('token')
// alert(token) //debug
if(token){
next()
} else {
if( to.path === '/login' || to.path === '/register' || from.path === '/register'){
next()
} else {
next('/login')
}
}
})