README: Add `torchaudio` to pip install command (#1355)
Summary:
Found that it was necessary to add `torchaudio` to the pip command to run `python install.py`.
Also I needed to run `pip install pyyaml`. Not sure if it is worth adding to the README.
Pull Request resolved: https://github.com/pytorch/benchmark/pull/1355
Reviewed By: mostafaelhoushi
Differential Revision: D42297825
Pulled By: xuzhao9
fbshipit-source-id: fa017a426f95067b11575350fcf7fcceb3c30e7c
