python3: Fix unicode compatibility python2/python3

Python3 enforces the distinction between byte strings and text strings
more rigorously than python2. So use six.text_type/six.u()
where appropriate

Change-Id: I890e19cb857e10f0292aabdaebaa8e7a7bd8db23
Signed-off-by: Chuck Short <chuck.short@canonical.com>
Merge "python3: Fix unicode compatibility python2/python3"