Update sphinx from 1.6.3 to 1.6.4

pyup-bot · pyup-bot · commit 06432d37d390 · 2017-09-26T04:30:43.000+03:00
diff --git a/requirements-doc.txt b/requirements-doc.txt
@@ -1,2 +1,2 @@
-sphinx==1.6.3
+sphinx==1.6.4
 sphinxcontrib-asyncio==0.2.0
