[Fix] Fix error when install from source

[ice-tong]

Motivation

I got an error when following the steps in the readme to install torcheval from the source.
It seems the packaging is an install requirement but not included in the requirements.txt.

git clone https://github.com/pytorch/torcheval
cd torcheval
pip install -r requirements.txt
python setup.py install

Modification

• Add packaging in the requirements.txt.

[bobakfb]

Hi @ice-tong thanks for the commit! This is a temporary issue with torchtnt, one of our requirements, and I know they are fixing it right now. My initial inclination is to just let them have that requirement since we don't need packaging directly to my knowledge.

[ice-tong]

Cool, I will close this PR～

[bobakfb]

thanks again @ice-tong this should be fixed now

[ananthsub]

Fixed by pytorch/tnt#298