Pin sphinx to 1.7.6 on travis.

Author: drvinceknight

.travis.yml

@@ -13,7 +13,7 @@ before_install:
   - sh -e /etc/init.d/xvfb start
 install:
   - pip install -r requirements.txt
-  - pip install sphinx
+  - pip install sphinx==1.7.6
   - pip install sphinx_rtd_theme
   - pip install docutils==0.12
   - pip install coverage