Fix a link to the open research corpus (#603)
Fix a link to the open research corpus (#603)

Missing "http://" caused it to think it is a relative path.
nafitzgerald/allennlp,allenai/allennlp,allenai/allennlp,allenai/allennlp,nafitzgerald/allennlp,allenai/allennlp,nafitzgerald/allennlp,nafitzgerald/allennlp