pylintrc needs update

[deborahgu]

Our .pylintrc is out of date, but simply updating it generates a large breakage report. We need to update .pylintrc, while making any required changes.

Acceptance Criteria

• Update .pylintrc, not manually, but according to the instructions at the top of the file
• Run pylint --django-settings-module=credentials.settings.test --rcfile=pylintrc acceptance_tests credentials *.py
  to see the list of required changes.
• Make all of the changes that are required.
• Verify that functionality still works and the tests still pass.