Fix reference to sso_server auth backend API

README.rst

@@ -33,7 +33,7 @@ The login service is fully stateless and can be easily replicated (for
 large setups). Authentication is ultimately performed by pluggable
 authentication modules (PAM and LDAP support are included in the
 source distribution). You can write your own following the API in
-``src/sso_server/sso_server/auth/base.py``.
+``src/sso_server/sso_server/auth/__init__.py``.
 
 
 Services