The ServiceStack.AuthWeb.Tests is an ASP.NET WebHost showing all the ServiceStack AuthProviders working within a single app.
Note the OAuth2 providers use additional configuration specified in the Web.config which requires that you register your own application to get your Consumer Key and Secret for your app. For testing purposes you can use the ServiceStack Test keys already embedded in the Web.config.
The OAuth2 section in the Authentication wiki provides the urls where you can register your application for each provider.