How to import node_modules vue component?

Hi! I am using Phoenix1.3.

npm install vue --save
npm install vue-core-image-upload --save

In the assets/js/app.js:
import Vue from "vue/dist/vue.js" works
But import VueCoreImageUpload from 'vue-core-image-upload' can not works.
The error:
app.js:61 Uncaught Error: Cannot find module 'vue-core-image-upload' from 'js/app.js'
How can i import the vue component?

Did you convert Phoenix to use Webpack 2.0 instead of brunch?

Others simply opt to keep the Vue.js project and Phoenix entirely separate.