Question: who was the governor general when the revolt of 1857 broke out
[{'answer': 'Lord Canning', 'provenance': [{'wikipedia_id': '590246', 'title': 'Indian Rebellion of 1857', 'start_paragraph_id': 3, 'start_character': 1014, 'end_paragraph_id': 3, 'end_character': 1026, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '590246', 'title': 'Indian Rebellion of 1857', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 1062, 'bleu_score': 0.8202156398514191, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6412733768204500380}, 'section': 'Section::::Abstract.'}]}]