Task 3.6 - Reproduce end-to-end ML pipelines

[mnrozhkov]

Branch: step-5-automate-ml-pipeline

Tasks:

• make sure that you've completed the Task 3.5
• run dvc repro (assume we do this for 1st time)
• run dvc repro (no changes, DVC skips all stages)
• run dvc repro -f (force running ML pipeline)
• run dvc repro train (run only train stage from dvc.yaml)
• update train stage configs and run dvc repro
• update src/stage/train.py code and run dvc repro
• remove reports/metrics.json and run dvc repro