Fixed TypeLoadException 

This is my first pull request so I hope I get this right.  I ran into the same error as issue#43.  After some research I found this: https://aspnetwebstack.codeplex.com/workitem/1646 .  After a little more work I removed the WebApi.Selfhost package and replaced it with the WebApi.Owin.Selfhost package.  This got rid of the TypeLoadException and I was able to use the self host console app.
This was added by Visual Studio since I used Visual Studio's text explorer to run the tests after I added an xunit test extension.  Basically it defines the project as a unit test project which in turn will show specific context menu's in Visual Studio, more information is in the Microsoft answer to this persons question here: https://connect.microsoft.com/VisualStudio/feedback/details/800245/vs2013rc-adds-to-vs2012-c-project-section-itemgroup

It can be removed although anyone using the VS test explorer it will get added again.  If you would like me to remove it please let me know.