Resolve build error

@gasparnagy This pull is to resolve the build error caused by pull #277 .  It wasn't a merge issue, I just did not commit the project file update that added a new file.  After adding this file, I was able to run the tests again.  

Sorry about that -- I've started working on SpecFlow using Xamarin Studio, and I'm trying to be very careful not to commit the sort of changes it wants to make to the solution and project files.  I guess I'm still figuring it out...