title: using moq with asp.net core while unit testing
body: <p>I am trying to write a very simple unit test in asp.net core using moq and xunit.
  But I am getting a error when I run the unit test.</p>
  
  <p>StackTrace: 
  at Moq.Mock<code>1..ctor(MockBehavior behavior, Object[] args)
     at Moq.Mock</code>1..ctor(MockBehavior behavior)
     at Moq.Mock`1..ctor()</p>
  
  <p>Could not load file or assembly 'System.Core, version=4.0.0'.</p>
  
  <p>Below is my code and project.json file.</p>
  
  <pre><code>{
    "version": "0.1.0-*",
    "testRunner": "xunit",
    "dependencies": {
      "Moq": "4.5.22",
      "xunit": "2.2.0-beta2-build3300",
      "dotnet-test-xunit": "2.2.0-preview2-build1029",
      "IntegraPay.Domain": {
        "version": "1.0.0-*",
        "target": "project"
      },
      "Integrapay.RegistrationApplication": {
        "version": "",
        "target": "project"
      },
      "Microsoft.NETCore.Portable.Compatibility": "1.0.1"
    },
    "frameworks": {
      "netcoreapp1.0": {
        "imports": [
          "dotnet5.6",
          "netcoreapp1.0",
          "net45",
          "net451"
        ],
        "dependencies": {
          "Microsoft.NETCore.App": {
            "type": "platform",
            "version": "1.0.0"
          }
        }
      }
    }
  }
  
  
   [Fact]
          public async void GetAttributes()
          {
              Mock&lt;IRegistrationRepository&gt; repo = new Mock&lt;IRegistrationRepository&gt;();
              RegistrationManager manager = new RegistrationManager(repo.Object);
              var item = await manager.CreateModel("1234");
          }
  </code></pre>