title: A valid Gruntfile could not be found
body: <p>I have followed this <a href="https://www.digitalocean.com/community/tutorials/how-to-install-a-mean-js-stack-on-an-ubuntu-14-04-server" rel="noreferrer">link</a> to try to install a <code>mean.js</code> stack on an ubuntu server.</p>
  
  <p>Regarding <code>grunt</code>, in <code>/opt/mean</code>, I have done</p>
  
  <pre><code>sudo npm install -g bower grunt-cli
  sudo npm install grunt --save-dev
  sudo npm install
  </code></pre>
  
  <p>However, <code>grunt</code> or <code>grunt jshint</code> inside the folder gives </p>
  
  <blockquote>
    <p>A valid Gruntfile could not be found. Please see the getting started
    guide for more information on how to configure grunt:
    <a href="http://gruntjs.com/getting-started" rel="noreferrer">http://gruntjs.com/getting-started</a> 
    Fatal error: Unable to find Gruntfile.</p>
  </blockquote>
  
  <p>Note that <code>npm start</code> works, and <code>http://server_domain_or_IP:3000</code> can display the sample application.</p>
  
  <p>Does anyone know how to fix the grunt error?</p>