fit and evaluate random forest classifier for example churn analysis

churn_fit_eval_rf.py

## Instantiate random forest classifier
rf = RandomForestClassifier(random_state=random_seed,
                            n_jobs=-1)

## Fit random forest classifier to training data
rf.fit(X_train_tf, y_train)

## Evaluate how the model performs on the test set
eval_clf(rf, X_test_tf, y_test);