Sync with oslo-incubator 569979adf

This syncs keystonemiddleware with oslo-incubator commit hash
569979adfd4237869bb50c7aaa02bc3fd4f0b413

First, remove the existing code to cleanup:
    $ rm -r keystonemiddleware/openstack/*

Then, sync from oslo-incubator:
    $ python update.py ../keystonemiddleware

Commits since last sync (55c5629):
----------------------------------
3d90045 Backport code for i18n to check lazy at runtime
ef37e03 Added missing jsonutils.dump() function
cb5a804 Move `mask_password` to strutils
de4adbc pep8: fixed multiple violations

Change-Id: If4d060be886ff0c3585b50534d35c87271491b47