Convert unicode for python3 portability

From http://docs.python.org/3.1/whatsnew/3.0.html:

"Python 3.0 uses the concepts of text and (binary) data instead of
Unicode strings and 8-bit strings."

Use six.text_type to Type for representing (Unicode) textual data. This
is unicode() in Python 2 and str in Python 3.

Change-Id: I3da268a714a34a8e626a2590f01b86e414dc3411
Signed-off-by: Chuck Short <chuck.short@canonical.com>
Merge "Convert unicode for python3 portability"