Update oslo-incubator log module

Changes -
 * Ability to customize default_log_levels for each project
 * Python 3: enable tests/unit/test_log.py
 * Move `mask_password` to strutils
 * update new requests logger to default WARN
 * Remove extra whitespace
 * Use oslo.messaging to publish log errors
 * pep8: fixed multiple violations
 * Fix common.log.ContextFormatter for Python 3
 * Mask passwords included without quotes at the ends of commands
 * Fixes a simple spelling mistake

Change-Id: I485e76890aa1a93415399c9457d6d87c7c5ed1c9
Merge "Update oslo-incubator log module"