title: ES2015 "import" not working in node v6.0.0 with with --harmony_modules option
body: <p>I am using node v6.0.0 and wanted to use ES2016 (ES6). However I realized that the "import" syntax is not working. Isn't "import" fundamental to for writing modular code in ES2015? I tried running node with <code>--harmony_modules</code> option as well but still got the same error about "import". Here's the code.</p>
  
  <p>Working code without "import":</p>
  
  <pre><code>'use strict';
  let sum = 0;
  class Number {
  
    addNumber(num1, num2) {
      return num1 + num2;
    }
  }
  let numberObj = new Number();
  sum = numberObj.addNumber(1,2);
  console.log("sum of two number 1 and 2 "+ sum);
  </code></pre>
  
  <p>Notworking code with "import":</p>
  
  <p>server.js</p>
  
  <pre><code>'use strict';
  import Number from "./Number";
  
  let sum = 0;
  
  
  let numberObj = new Number();
  
  sum = numberObj.addNumber(1,2);
  console.log("sum of two number 1 and 2 "+ sum);
  </code></pre>
  
  <p>Number.js</p>
  
  <pre><code>'use strict';
  export default class Number {
  
    addNumber(num1, num2) {
      return num1 + num2;
    }
  }
  </code></pre>
  
  <p>I also checked <a href="http://node.green/">http://node.green/</a> to see the supported es6 however not able to understand why it doesn't work with --harmony_modules option. Please help.</p>