Question: who was the first black football player to win the heisman trophy
[{'answer': 'Ernest Davis', 'provenance': [{'wikipedia_id': '2778487', 'title': 'Ernie Davis', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 12, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2778487', 'title': 'Ernie Davis', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 161, 'bleu_score': 0.898150350240263, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13803277260411610293}, 'section': 'Section::::Abstract.'}]}]