Fix a bad edit for cython syntax highlighting.

conf.py

@@ -29,7 +29,7 @@ highlight_language = 'cython'
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-extensions = ['ipython_console_highlighting', 'sphinx.ext.pngmath', 'sphinx.ext.todo']
+extensions = ['ipython_console_highlighting', 'cython_highlighting', 'sphinx.ext.pngmath', 'sphinx.ext.todo']
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']