docs: Pin version of sphinxcontrib-asyncio

The just-released version 0.3.0 is incompatible with our older pinned
version of sphinx.

diff --git a/docs/requirements.txt b/docs/requirements.txt
index 852493572bb31e6c3cad602e4dc05e44024675be..7599072be187b2a264ff53560f42f2fbe7ac5c3a 100644 (file)
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,4 +1,4 @@
 sphinx>1.8.2,<2.1
-sphinxcontrib-asyncio
+sphinxcontrib-asyncio==0.2.0
 sphinx_rtd_theme
 Twisted