title: How can I set an environment variable as gulp task?
body: <p>I don't want type the extra arguments <code>NODE_ENV='production' gulp</code> every time I run gulp to set an environment variable.</p>
  
  <p>I would rather set the environment variable <strong>from within gulp via a task</strong>.</p>
  
  <p>What would be a good way to achieve this?</p>