title: Could not install package 'Microsoft.CodeDom.Providers.DotNetCompilerPlatform 2.0.1'
body: <p>Background: I had Microsoft.CodeDom.Providers.DotNetCompilerPlatform 2.0.1' and tried to upgrade to the the newest version 3.6.0 in Visual Studio 2017 in my web project using the Nuget package manager and get the error:</p>
  <pre><code>Could not install package 'Microsoft.CodeDom.Providers.DotNetCompilerPlatform 3.6.0'. 
  You are trying to install this package into a project that targets '.NETFramework,Version=v4.0', 
  but the package does not contain any assembly references or content files that are compatible with 
  that framework. 
  </code></pre>
  <p>I tried to go back to the version 2.0.1 and it won't install that now either, even though that was the version that was installed before I tried to upgrade. I can uninstall all of it, but then I 'think' I am not using the Roselyn compiler (do I need to?).
  Any help would be appreicated either to get the newest version installed, get 2.01 installed, or a clear answer that I don't need the Microsoft.CodeDom.Providers.DotNetCompilerPlatform package. Thank you!</p>