Add google.oauth2.flow - utility for doing OAuth 2.0 Authorization Flow (#100)

diff --git a/docs/conf.py b/docs/conf.py
index b045c8c..5dbac87 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -370,6 +370,8 @@
     'python': ('https://docs.python.org/3.5', None),
     'urllib3': ('https://urllib3.readthedocs.io/en/stable', None),
     'requests': ('http://docs.python-requests.org/en/stable', None),
+    'requests-oauthlib': (
+        'http://requests-oauthlib.readthedocs.io/en/stable', None),
 }
 
 # Autodoc config