python3: python3 binary/text data compatbility
python3: python3 binary/text data compatbility

Python3 enforces the distinction between byte strings
far more rigorously than Python 2 does; binary data
cannot be automatically coerced to or from text data.

Use six to provide a fake file object for textual data.
It provides an alias for StringIO.StringIO in python2
and io.StringIO in python3

Change-Id: I65897bb0cca2cbeb5819a769b98645c9eb066401
Signed-off-by: Chuck Short <753a8074f04ffd62a8fff7516e3ae689be8e35ad@canonical.com>

JioCloud/oslo.middleware,chungg/oslo.middleware,varunarya10/oslo.middleware,openstack/oslo.middleware