Log Message:
Update py-six to 1.10.0:

1.10.0
------

- Issue #122: Improve the performance of `six.int2byte` on Python 3.

- Pull request #55 and issue #99: Don't add the `winreg` module to `six.moves`
  on non-Windows platforms.

- Pull request #60 and issue #108: Add `six.moves.getcwd` and
  `six.moves.getcwdu`.

- Pull request #64: Add `create_unbound_method` to create unbound methods.