title: Installing PyTorch with CUDA in setup.py
body: <p>I'm trying to specify PyTorch with CUDA in install_requires. The command to install with pip is</p>
  <p><code>pip install torch==1.8.0+cu111 torchvision==0.9.0+cu111 torchaudio===0.8.0 -f https://download.pytorch.org/whl/torch_stable.html</code></p>
  <p>How do I do that in the setup.py install_requires?</p>