Fix typo in simple_seq2seq.py docstring (#587)
Fix typo in simple_seq2seq.py docstring (#587)


nafitzgerald/allennlp,nafitzgerald/allennlp,allenai/allennlp,nafitzgerald/allennlp,nafitzgerald/allennlp,allenai/allennlp,allenai/allennlp,allenai/allennlp