docs: pin Sphinx to <2.0

blueyed · blueyed · commit f4bcb4402588 · 2019-03-13T02:36:15.000+01:00
Ref: #4912
diff --git a/doc/en/requirements.txt b/doc/en/requirements.txt
@@ -1,4 +1,4 @@
 pygments-pytest>=1.1.0
-sphinx>=1.8.2
+sphinx>=1.8.2,<2.0
 sphinxcontrib-trio
 sphinx-removed-in>=0.1.3
