Update oslo-incubator log.py to a01f79c

This updates the log module from oslo-incubator to
a01f79c3050962fd744239956e9654407d14ea1f

 $ git checkout a01f79c3050962fd744239956e9654407d14ea1f
 $ python update.py --nodeps --base keystone \
     --dest-dir ../keystone --modules log

This includes a fix for the deprecated logger that caused the
deprecated message to be printed multiple times rather than once.

Change-Id: I6174b064205adcdc9fb966a9e01eb5190b5b730e
Closes-Bug: #904307
Closes-Bug: #1266812
Merge "Update oslo-incubator log.py to a01f79c"