title: Vue JS focus next input on enter
body: <p>I have 2 inputs and want switch focus from first to second when user press Enter.
  I tried mix jQuery with Vue becouse I can't find any function to focus on something in Vue documentation:</p>
  
  <pre><code>&lt;input v-on:keyup.enter="$(':focus').next('input').focus()"
      ...&gt;
  &lt;input  ...&gt;
  </code></pre>
  
  <p>But on enter I see error in console:</p>
  
  <pre><code>build.js:11079 [Vue warn]: Property or method "$" is not defined on the instance but referenced during render. Make sure to declare reactive data properties in the data option. (found in anonymous component - use the "name" option for better debugging messages.)warn @ build.js:11079has @ build.js:9011keyup @ build.js:15333(anonymous function) @ build.js:10111
  build.js:15333 Uncaught TypeError: $ is not a function
  </code></pre>