Compile of several minor fixes for ML examples:
1. In TutorialStepByStepExample we running 17 examples
First 12 logging is pretty good and looks like "Tutorial step N: name" -> model -> accuracy -> "Tutorial step N: completed"
But then starting with 13 this pattern is kind of broke, step start and step completion is missing
2. Step_8_CV_with_Param_Grid_and_metrics_and_pipeline is haven't step completion log
3. Complete log for Step_9_Scaling_With_Stacking looks like 'Tutorial step 5 (scaling) example completed'