python-six

- update to 1.6.1:
- Raise an AttributeError for six.moves.X when X is a module not available in
the current interpreter.
- Raise an AttributeError for every attribute of unimportable modules.
- Issue #56: Make the fake modules six.moves puts into sys.modules appear not to
have a __path__ unless they are loaded.
- Pull request #28: Add support for SplitResult.
- Issue #55: Add move mapping for xmlrpc.server.
- Pull request #29: Add move for urllib.parse.splitquery.