title: C# interactive window won't reference my code
body: <p>In Visual Studio 2017 I am trying to run some code in the c# Interactive Window.
  This works for very simple cases (e.g. using System)
  However, when I try and reference slightly more obscure libraries it fails</p>
  
  <pre><code>using Microsoft.AspNetCore.Cryptography.KeyDerivation;
  </code></pre>
  
  <blockquote>
    <p>(1,17): error CS0234: The type or namespace name 'AspNetCore' does not
    exist in the namespace 'Microsoft' (are you missing an assembly
    reference?)</p>
  </blockquote>
  
  <p>This is a dot net core 2.0 project, and it has been suggested that I can right click on the project and select "Initialize Interactive with Project", however this option does not appear for me on either the project or solution.</p>
  
  <p>I need to know how to add references to code libraries for the interactive window.</p>