The last in this series is splitting the the data into train and test then attempt a prediction with the test data set. It is possible to do this early in the process, but no harm in waiting as long as you do it eventually.
First off once again lets load the data. Notice i have added a new package for splitstackshape which provides a method to stratify the data.
If you are more interested in Python i have created a notebook using the same dataset but with the python solution here.