Use vendored version of ``six`` in pyopenssl.
Fixes import errors like when importing requests.
MODIFY
CHANGES.rst
CHANGES.rst
@@ -15,6 +15,8 @@ dev (master)
* Fixed compatibility for cookiejar. (Issue #1229)
+* pyopenssl: Use vendored version of ``six``.
+
* ... [Short description of non-trivial change.] (Issue #)

MODIFY
CONTRIBUTORS.txt
CONTRIBUTORS.txt
@@ -230,5 +230,8 @@ In chronological order:
* Tuukka Mustonen <tuukka.mustonen@gmail.com>
* Add counter for status_forcelist retries.
+* Erik Rose <erik@mozilla.com>
+ * Bugfix to pyopenssl vendoring
+
* [Your name or handle] <[email or website]>
* [Brief summary of your changes]

MODIFY
urllib3/contrib/pyopenssl.py
urllib3/contrib/pyopenssl.py
@@ -59,7 +59,7 @@ except ImportError: # Platform-specific: Python 3
import logging
import ssl
-import six
+from ..packages import six
import sys
from .. import util

Use vendored version of ``six`` in pyopenssl.

Fixes import errors like https://github.com/certbot/certbot/issues/4886 when importing requests.