title: project.json in ASP.NET 5 and MVC6
body: <p>When I looked at the tutorials of MVC6, I get confused the usage of <a href="https://github.com/aspnet/Home/wiki/Project.json-file" rel="noreferrer">project.json</a>. By my understanding this file is used to specify the project dependencies.</p>
  
  <p>Prior to ASP.NET 5, we use nuget to manage the dependencies. But from some limited MVC6 samples I have seen I don't see people mention <code>package.config</code> any more.</p>
  
  <p>Please help me to understand:</p>
  
  <ul>
  <li>Do we still use <code>nuget</code> to upgrade all depending components?</li>
  <li>Or we have to modify the <code>project.json</code> manually?</li>
  </ul>