title: Visual studio not detecting package update
body: <p>I have a dependency on specific nuget package. When I update my solution to use new package version and commit/push solution to remote GIT repository, other contributors to solution, after pull, are still using old DLL version of nuget package, even though package-restore is activated. However, when they open CSPROJ file, it shows that reference should be to the new version. Basically Visual Studio is not generating any warning/error if there is a mismatch between used DLL from bin/obj folder and referenced DLL in csproj file. To be more concise:</p>
  
  <ol>
  <li>Solution uses DLL version 0.5</li>
  <li>I upgrade via Nuget to DLL version 0.6</li>
  <li>My Visual Studio shows that version 0.6 is used</li>
  <li>I commit/push solution to GIT</li>
  <li>Another colleague pulls solution from GIT</li>
  <li>His Visual Studio shows DLL version 0.5, there is no error/warning</li>
  <li>His CSPROJ file references DLL version 0.6</li>
  <li>Solution fails on runtime as there is change in internal implementation</li>
  </ol>
  
  <p>How do we fix this:</p>
  
  <ol>
  <li>Colleague deletes his bin/obj</li>
  <li>Visual Studio notices that DLL's are missing</li>
  <li>He uses Manage Nuget Packages on solution level and just clicks OK, nothing else</li>
  <li>Nuget downloads DLL's and issue is solved</li>
  </ol>
  
  <p>Now this is really stupid workaround and in my opinion this should be automated. Is there anything that we might be doing wrong that is causing this to happen?</p>