title: NuGet not updating project references
body: <p>I recently migrated all my Visual Studio 2013 projects to Visual Studio 2015 and followed the steps documented in this <a href="https://docs.nuget.org/consume/package-restore/migrating-to-automatic-package-restore" rel="noreferrer">article</a> by Nuget to make sure that automatic package restore is still working, in short</p>
  
  <ul>
  <li>I deleted the Nuget.exe and Nuget.target files from source control and disk</li>
  <li>I updated all project files and deleted the sections related to Nuget</li>
  </ul>
  
  <p>I'm experiencing a problem when I'm updating Nuget packages, it is not updating the project references to point to the newest dll versions. I can see that the newest packages was installed though. This problem is also not related to specific packages.</p>
  
  <p>Has anyone else experienced a problem like this?</p>