Question: when did season 2 of stranger things start
[{'answer': 'October 27 , 2017', 'provenance': [{'wikipedia_id': '46301800', 'title': 'Stranger Things', 'start_paragraph_id': 54, 'start_character': 198, 'end_paragraph_id': 54, 'end_character': 217, 'bleu_score': 1.0, 'section': 'Section::::Release.\n'}]}]