title: what does grunt "test command" do on npm init
body: <p>I'm trying to learn grunt. When I run npm init, I get a prompt in the process of creating a package.json file that asks for "test command" - I'm not sure how to utilize this, or what it's expecting. It doesn't seem to be well documented. If I leave it blank, I get this in the resulting package.json file:</p>
  
  <pre><code>"scripts": {
      //"test": "echo \"Error: no test specified\" &amp;&amp; exit 1"
    },
  </code></pre>
  
  <p>Can anybody shed some light on how to set up a test script?</p>