title: template string not getting transpiled properly
body: <pre><code>const ROOT_URL = "http://reduxblog.herokuapp.com/api/posts";
  const API_KEY = "?key=PWEFBIUB";
  const url = `$(ROOT_URL)/posts$(API_KEY)`
  </code></pre>
  
  <p>Is getting transpiled into:-</p>
  
  <pre><code>var ROOT_URL = "http://reduxblog.herokuapp.com/api/posts";
  var API_KEY = "?key=PWEFBIUB";
  var url = '$(ROOT_URL)/posts$(API_KEY)';
  </code></pre>
  
  <p>Why this happening I dont know. But babel is not working properly. Please help.</p>