Bump sphinx from 2.4.0 to 2.4.1 (#4567)

dependabot-preview[bot] · web-flow · commit f80029b553ec · 2020-02-11T14:45:54.000Z
diff --git a/requirements/doc.txt b/requirements/doc.txt
@@ -1,4 +1,4 @@
-sphinx==2.4.0
+sphinx==2.4.1
 sphinxcontrib-asyncio==0.2.0
 pygments==2.5.2
 aiohttp-theme==0.1.6
