title: Show modal on Vue
body: <p>Trying to show a modal with the following code:</p>
  
  <pre><code>import VModal from 'vue-js-modal';
  
  Vue.use(VModal);
  </code></pre>
  
  <p>On template:</p>
  
  <pre><code>&lt;modal name="hello-world"&gt;
    hello, world!
  &lt;/modal&gt;
  </code></pre>
  
  <p>Vue part:</p>
  
  <pre><code>myMethod() {
      this.$modal.show('hello-world');
  }
  </code></pre>
  
  <p>When trying to call myMethod(), I get the error "Cannot read property 'show' of undefined". Any ideas?</p>