title: SpecFlow "Generate Test Definition" context menu missing in VS2015
body: <p>I'm trying out VS2015 and writing SpecFlow feature files. When I right click on the file, I cannot find "Generate Test Definitions" context menu. This happens only in "Class Library (Package)" which is obviously DNX 5.0 library.</p>
  
  <p>Here is my project.json:</p>
  
  <pre><code>{
      "version": "1.0.0-*",
      "description": "",
      "authors": [ "" ],
      "tags": [ "" ],
      "projectUrl": "",
      "licenseUrl": "",
  
      "dependencies": {
          "SpecFlow": "1.9.0",
          "SpecFlow.xUnit": "1.0.2",
          "xunit": "2.1.0-beta3-build3029",
          "xunit.extensions": "2.0.0"
      },
  
      "frameworks": {
          "dnx451": { },
          "dnxcore50": {
          "dependencies": {
              "System.Collections": "4.0.10-beta-22816",
              "System.Linq": "4.0.0-beta-22816",
              "System.Threading": "4.0.10-beta-22816",
              "Microsoft.CSharp": "4.0.0-beta-22816"
          }
      }
  }
  </code></pre>
  
  <p>And I have added SpecFlow Visual Studio 2015 extensions.</p>
  
  <p>Am I missing something here?</p>
  
  <p>But if I try the same in a normal Class Library that works fine.</p>