python3: handle module moves in log

Python 3 reorganized the standard library and moved several functions to different modules.
Six provides a consistent interface to them through the fake six.moves module.

Change-Id: I040fe8e0e4640e7cdd805ab49891b94da6cc4595
Signed-off-by: Chuck Short <chuck.short@canonical.com>
Merge "python3: handle module moves in log"