[probably_wrong]

I wouldn't upgrade just yet if I were you, because part of the seq2seq code is still broken - more specifically, "there seems to be a problem with deepcopy of RNNCell"[1]. The bug is still open[2], and has been for a while.

[1] https://stackoverflow.com/a/44594376

[2] https://github.com/tensorflow/tensorflow/issues/8191