vice: <code>ratings</code>.</p><p>The <code>ratings</code> service is a small web app written in
<a href=https://nodejs.org/en/>Node.js</a> that can run on its own. It performs similar
actions to those of other web apps:</p><ul><li>Listen to the port it receives as a parameter.</li><li>Expect <code>HTTP GET</code> requests on the <code>/ratings/{productID}</code> path and return the
ratings of the product matching the value the client specifies for <code>productID</code>.</li><li>Expect <code>HTTP POST</cod