Have you tried installing it via
https://download.pytorch.org/whl/cu100/torch_stable.html

Just  do
pip install torch-1.2.0-cp36-cp36m-manylinux1_x86_64.whl
1.2 is torch version and cp36 is python 3.6 and it is for x86_64 architecture so I would go to first link and choose the right python version and architecture and then install it.