Add console capture to ExecuteCases.cs

public class ExecuteCases : InstanceBehavior
{
    public void Execute(Fixture fixture)
    {
        foreach (var @case in fixture.Cases)
        {
            using (var console = new RedirectedConsole())
            {
                var stopwatch = new Stopwatch();
                stopwatch.Start();

                try
                {
                    fixture.CaseExecutionBehavior.Execute(@case, fixture.Instance);
                }
                catch (Exception exception)
                {
                    @case.Fail(exception);
                }

                stopwatch.Stop();

                @case.Duration = stopwatch.Elapsed;
                @case.Output = console.Output;
            }

            Console.Write(@case.Output);
        }
    }
}