title: ES2015 Babel String Interpolation not working with apostrophe (but does with double quotes)
body: <p>I am using babel / grunt to learn some ES2015.</p>
  
  <p>According to <a href="https://stackoverflow.com/questions/3149192/difference-between-single-quotes-and-double-quotes-in-javascript">this post</a> there is no real difference in Javascript between single and double quotes. i.e. 'test' and "test".</p>
  
  <p>When trying string interpolation though, it seems there is an issue with babeljs (or more likely - me). What is wrong with the code below please? </p>
  
  <p>According to <a href="https://developers.google.com/web/updates/2015/01/ES6-Template-Strings?hl=en" rel="noreferrer">this document</a>, it seems both should work. There are no errors in the Chrome console.</p>
  
  <p><strong>Working Js:</strong></p>
  
  <pre><code>var name = "Bob", time = "today";
  alert(`Hello ${name}, how are you ${time}?`);
  </code></pre>
  
  <p><strong>Transpiles to:</strong></p>
  
  <pre><code>var name = "Bob",
      time = "today";
  alert("Hello " + name + ", how are you " + time + "?");
  </code></pre>
  
  <p>Provides the expected result.</p>
  
  <p><strong>Failing Js:</strong></p>
  
  <pre><code>var forename = 'bob', surname = 'test';
  alert('hello ${forename} ${surname} - how are you?');
  </code></pre>
  
  <p><strong>Transpiles to:</strong></p>
  
  <pre><code>var forename = "bob",
      surname = "test";
  alert("hello ${forename} ${surname} - how are you?");
  </code></pre>
  
  <p>and provides the following output:</p>
  
  <p><img src="https://i.stack.imgur.com/H4bvh.png" alt="enter image description here"></p>