Fix travis docs failing with Sphinx 1.8.0

Sphinx pinned to 1.7

See sphinx-doc/sphinx#5417

1 files changed, 1 insertions, 1 deletions

diff --git a/tox.ini b/tox.ini
index 3e8688c6b..52626d3e2 100644
--- a/tox.ini
+++ b/tox.ini
@@ -180,7 +180,7 @@ sitepackages = False
 changedir = docs
 deps =
     {[testenv]deps}
-    sphinx
+    sphinx==1.7.*
 whitelist_externals =
     {[testenv]whitelist_externals}