Update flake8 to 3.7.5#570

sliverc merged 2 commits intomasterdjango-json-api/django-rest-framework-json-api:masterfrom

pyup-update-flake8-3.6.0-to-3.7.5django-json-api/django-rest-framework-json-api:pyup-update-flake8-3.6.0-to-3.7.5Copy head branch name to clipboard