title: Updating solution to .net framework 4.7: issue with Roslyn
body: <p>I'm trying to update a solution that uses roslyn to 4.7.
  When updating the nuget packages I get the following error:</p>
  
  <blockquote>
    <p>One or more unresolved package dependency constraints detected in the existing packages.config file. All dependency constraints must be resolved to add or update packages. If these packages are being updated this message may be ignored, if not the following error(s) may be blocking the current package operation: 'System.Security.Cryptography.Algorithms 4.3.0 constraint: System.IO (>= 4.3.0)'</p>
  </blockquote>
  
  <p>And then, when trying to use Roslyn, I get an exception running the following code:</p>
  
  <pre><code>var compilation = CSharpCompilation.Create("MyCompilation", new[] {syntaxTree}, references);
  var diag = compilation.GetDiagnostics();
  </code></pre>
  
  <p>The Exception is:</p>
  
  <blockquote>
    <p>Managed Debugging Assistant 'BindingFailure'  occurred
      HResult=0x00000000
      Message=<strong>Managed Debugging Assistant 'BindingFailure' :</strong> 'The assembly with display name 'System.Security.Cryptography.Algorithms' failed to load in the 'LoadFrom' binding context of the AppDomain with ID 1. The cause of the failure was: System.IO.FileLoadException: Could not load file or assembly 'System.Security.Cryptography.Algorithms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)'</p>
  </blockquote>
  
  <p>Any idea about how to fix?</p>