Require at least Sphinx 1.0 to build the documentation
diff --git a/doc/conf.py b/doc/conf.py
index c7bcb13..b28c4c9 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -24,7 +24,7 @@
 # -- General configuration -----------------------------------------------------
 
 # If your documentation needs a minimal Sphinx version, state it here.
-#needs_sphinx = '1.0'
+needs_sphinx = '1.0'
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.