Migrate to PyTorch 1.2 about geo-deep-learning

[ymoisan]

Travis CI already uses 1.1. All we have to do is modify our own dev/test environments.

[mpelchat04]

Changes in Pytorch 1.2.0:
/conda_envs/env_name/lib/python3.6/site-packages/torch/optim/lr_scheduler.py:82:
UserWarning: Detected call of lr_scheduler.step() before optimizer.step(). In PyTorch 1.1.0 and later, you should call them in the opposite order: optimizer.step() before lr_scheduler.step(). Failure to do this will result in PyTorch skipping the first value of the learning rate schedule.See more details at https://pytorch.org/docs/stable/optim.html#how-to-adjust-learning-rate
"https://pytorch.org/docs/stable/optim.html#how-to-adjust-learning-rate", UserWarning)