Update six to 1.12.0

[pyup-bot]

This PR updates six from 1.8.0 to 1.12.0.

Changelog

### 1.12.0 ``` ------ - Issue 259, pull request 260: `six.add_metaclass` now preserves `__qualname__` from the original class. - Pull request 204: Add `six.ensure_binary`, `six.ensure_text`, and `six.ensure_str`. ``` ### 1.11.0 ``` ------ - Pull request 178: `with_metaclass` now properly proxies `__prepare__` to the underlying metaclass. - Pull request 191: Allow `with_metaclass` to work with metaclasses implemented in C. - Pull request 203: Add parse_http_list and parse_keqv_list to moved urllib.request. - Pull request 172 and issue 171: Add unquote_to_bytes to moved urllib.parse. - Pull request 167: Add `six.moves.getoutput`. - Pull request 80: Add `six.moves.urllib_parse.splitvalue`. - Pull request 75: Add `six.moves.email_mime_image`. - Pull request 72: Avoid creating reference cycles through tracebacks in `reraise`. ``` ### 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. ``` ### 1.9.0 ``` ----- - Issue 106: Support the `flush` parameter to `six.print_`. - Pull request 48 and issue 15: Add the `python_2_unicode_compatible` decorator. - Pull request 57 and issue 50: Add several compatibility methods for unittest assertions that were renamed between Python 2 and 3. - Issue 105 and pull request 58: Ensure `six.wraps` respects the *updated* and *assigned* arguments. - Issue 102: Add `raise_from` to abstract out Python 3's raise from syntax. - Issue 97: Optimize `six.iterbytes` on Python 2. - Issue 98: Fix `six.moves` race condition in multi-threaded code. - Pull request 51: Add `six.view(keys|values|itmes)`, which provide dictionary views on Python 2.7+. - Issue 112: `six.moves.reload_module` now uses the importlib module on Python 3.4+. ```

Links

- PyPI: https://pypi.org/project/six - Changelog: https://pyup.io/changelogs/six/ - Repo: https://github.com/benjaminp/six - Docs: https://pythonhosted.org/six/