Merge flake8 configurations

[mthrok]

Currently we have tox.ini with only flake8-related configuration and .flake8.
In the workflow of torchaudio development we do not use tox.
I do not know the origin of them but we should merge these into .flake8.
PyTorch repo does not have tox.ini either so it's simpler for us to do the same thing.

[bhargavkathivarapu]

@mthrok Along with flake8 configurations can we include precommit hooks , so that style issues , imports ordering ,unused imports etc won't come into commits. It seems Pytorch already has a pre commit setup( https://github.com/pytorch/pytorch/blob/master/tools/git-pre-commit ) . May be we can extended that for this repo or use configuarations like isort , pre-commit along with flake8

[mthrok]

@bhargavkathivarapu

Thanks for the suggestion. However, in my experience, this kind of pre-commit hook is more counter-productive than helpful. I often push my WIP branch for the purpose of backup, because my development workflow sometimes involve multiple machines on network. I polish my changes only before publishing a PR and pre-commit hook only helps in those occasions.

Also one has to install pre-commit hook manually, so there is no automatic enforcement.

[krishnakalyan3]

@mthrok, I would like to take a stab at this.

From what I understand
https://github.com/pytorch/audio/blob/master/.flake8
https://github.com/pytorch/audio/blob/master/tox.ini

should be merged to .flake8 and tox.ini removed. Is this understanding correct?.