Not quite sure why the test is failing, but I did solve my problem.
I changed the registration from this:
container.Register(Component.For<ISimpleService>()
.ImplementedBy<SimpleService>()
.AsWcfService(new DefaultServiceModel()
.AddBaseAddress("http://localhost:515")
.PublishMetadata(x => x.EnableHttpGet())
.AddEndPoints(WcfEndpoint.ForContract<ISimpleService>().BoundTo(new BasicHttpBinding()).At("SimpleService"))));
to this:
container.Register(Component.For<ISimpleService>()
.ImplementedBy<SimpleService>()
.AsWcfService(new DefaultServiceModel()
.AddBaseAddress("http://localhost:515/SimpleService")
.PublishMetadata(x => x.EnableHttpGet())
.AddEndPoints(WcfEndpoint.ForContract<ISimpleService>().BoundTo(new BasicHttpBinding()))));
When defining the BaseAddress I now include the "SimpleService" and remove it when defining the EndPoints.