Update sphinx to 2.2.0#692

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

pyup-update-sphinx-2.1.2-to-2.2.0django-json-api/django-rest-framework-json-api:pyup-update-sphinx-2.1.2-to-2.2.0Copy head branch name to clipboard