title: Unable to import/export vuejs components
body: <p>I have a folder like this. </p>
  
  <pre><code>VueTree
    components
      Classic.vue
      Modern.vue
    index.js
  </code></pre>
  
  <p>Classic and Modern are simple components with <code>template</code>, <code>export default {}</code> and a <code>style</code>. 
  I am calling both inside <code>index.js</code> as:</p>
  
  <pre><code>import Classic from './components/Classic.vue'
  import Modern from './components/Modern.vue'
  
  const VueTree= {
    Classic ,
    Modern 
  }
  
  export default VueTree
  </code></pre>
  
  <p>So, when I import this module as: </p>
  
  <pre><code>import {Classic , Modern } from '../../modules/VueTree/index.js'
  </code></pre>
  
  <p>I get this error</p>
  
  <p>Unknown custom element:  - did you register the component correctly? For recursive components, make sure to provide the "name" option.</p>
  
  <p>I have <code>name: "Classic"</code> inside my components and I am including the in the current file using <code>components: { Classic },</code> but I get the same error. </p>
  
  <p>It only works if I export only one component as: </p>
  
  <pre><code>import Classic from './components/Classic.vue'
  import Modern from './components/Modern.vue'
  export default Classic
  </code></pre>
  
  <p>this will work and include the classic, but I can't export both of them like seen in this example <a href="https://github.com/greyby/vue-spinner/blob/master/src/index.js" rel="nofollow noreferrer">https://github.com/greyby/vue-spinner/blob/master/src/index.js</a></p>