Question: who was the winner of britain's got talent 2014
[{'answer': 'Collabro', 'provenance': [{'wikipedia_id': '39618534', 'title': "Britain's Got Talent (series 8)", 'start_paragraph_id': 2, 'start_character': 38, 'end_paragraph_id': 2, 'end_character': 46, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]