Code auditing standards

[Chris Adams]

Currently if you run pep8, flake8, etc. over the codebase you'll get a number of warnings for long lines, unused imports, etc. which makes it easy to miss more important warnings.

In the interests of making it easier to clean these up, I would like to propose that we add some project-level config for pep8 / flake8 and isort to encourage using those tools (and editor plugins) to tidy things up. In the interest of proposing a lightweight "policy", https://gist.github.com/acdha/8639675 has what I'm using now.

Thoughts?

Chris