Adding a functional test for anti forgery.

#333 
Could you add files \ actions once they get used in your test? This comment works for the second action `public async Task<ActionResult> Login(LoginViewModel model, string returnUrl)` this controller etc. Additionally, if the purpose of this test is to verify you can have multiple invocations of `@Html.AntriforgeryToken()`, you can remove a lot of the cruft that's part of the page. It just acts as noise and doesn't add to the test coverage.