More build scripts for testing

FlubuCore_TestAsyncTargets.cs

public class DefaultTestScript : DefaultBuildScript
{           
    protected override void ConfigureTargets(ITaskContext context)
    {
        var doExample = context.CreateTarget("DoExample")
                .Do(t => { throw new Exception("error on purpose."); });
        var doExample2 = context.CreateTarget("DoExample2")
                .Do(t => { Console.WriteLine("from doExample2"); });
        var test = context.CreateTarget("test")
            .Do(t => { Console.WriteLine("from test"); });

        context.CreateTarget("Rebuild")
            .SetAsDefault()
            .AddTask(t => t.Do(x => { Console.WriteLine("from rebuild"); }))
            .DependsOnAsync(doExample, doExample2)
            .DependsOn(test);
    }
}
/*
Expected result:

Target      Duration  Status
----------------------------------
DoExample   00:00:00  Failed
DoExample2  00:00:00  Finished
Test        00:00:00  NotRan
Rebuild     00:00:00  Failed

BUILD FAILED
*/