title: ES6 import happening before .env import
body: <p>Trying to use an environment variable from my dotenv file crashes my app because it seems the dotenv file is not loaded on time.</p>
  
  <pre><code>// server.js
  require('dotenv').config({ silent: process.env.NODE_ENV === 'production' })
  console.log("Here is the env var: ", process.env.SPARKPOST_API_KEY) // works
  import express from 'express'
  import routes from './routes'
  (...)
  app.use('/api', routes);
  
  // routes/index.js
  import somecontroller from '../controllers/somecontroller'
  const routes = express.Router()
  routes.use('/somecontroller', somecontroller)
  
  // somecontroller.js
  import sendEmail from '../helpers/sparkpost'
  
  // ./helpers/sparkpost.js
  import SparkPost from 'sparkpost'
  var sparky = new SparkPost()  // uses process.env.SPARKPOST_API_KEY
  export default function sendEmail() {
  }
  </code></pre>
  
  <p>crashes with error</p>
  
  <pre><code>Error: Client requires an API Key.
  </code></pre>
  
  <p>The API key is there, so it seems that sparkpost.js is instantiating <code>new SparkPost()</code> before the <code>dotenv</code> file gets loaded.</p>
  
  <p>How do I work around this?</p>