Python 3.7 warnings with CPU training

[ronaldtse]

These warnings don't seem to affect training but probably should be fixed:

[W ParallelNative.cpp:212] Warning: Cannot set number of intraop threads after parallel work has started or after set_num_threads call when using native 

[W ParallelNative.cpp:212] Warning: Cannot set number of intraop threads after parallel work has started or after set_num_threads call when using native parallel backend (function set_num_threads)
                                                                                                                    /Users/me/.pyenv/versions/3.7.11/lib/python3.7/site-packages/torch/nn/functional.py:652: UserWarning: Named tensors and all their associated APIs are an experimental feature and subject to change. Please do not use them for anything important until they are released as stable. (Triggered internally at  ../c10/core/TensorImpl.h:1156.)

  return torch.max_pool1d(input, kernel_size, stride, padding, dilation, ceil_mode)

Originally posted by @ronaldtse in #22 (comment)