Training command line does not include dev set

[edmcman]

Training command line does not include dev set:

python exp.py \
    train \
    --cuda \
    --work-dir=exp_runs/dire.hybrid \
    --extra-config='{ "data": {"train_file": "data/preprocessed_data/train-shard-*.tar" }, "decoder": { "input_feed": false, "tie_embedding": true }, "train": { "evaluate_every_nepoch": 5, "max_epoch": 60 } }' \
    data/config/model.hybrid.jsonnet

Fixed in ed-wip branch, close when merged.