Drop use of 'oslo' namespace package

The Oslo libraries have moved all of their code out of the 'oslo'
namespace package into per-library packages. The namespace package was
retained during kilo for backwards compatibility, but will be removed by
the liberty-2 milestone. This change removes the use of the namespace
package, replacing it with the new package names.

The patches in the libraries will be put on hold until application
patches have landed, or L2, whichever comes first. At that point, new
versions of the libraries without namespace packages will be released as
a major version update.

Please merge this patch, or an equivalent, before L2 to avoid problems
with those library releases.

Blueprint: remove-namespace-packages
https://blueprints.launchpad.net/oslo-incubator/+spec/remove-namespace-packages

Change-Id: I9891564317aa3cf84874debdc966e48fb270455e

os_brick/i18n.py

@@ -18,7 +18,7 @@ See http://docs.openstack.org/developer/oslo.i18n/usage.html .
 
 """
 
-from oslo import i18n
+import oslo_i18n as i18n
 
 DOMAIN = 'os-brick'
 

os_brick/tests/base.py

@@ -20,8 +20,8 @@ import os
 
 import fixtures
 import mock
-from oslo.utils import strutils
 from oslo_log import log as oslo_logging
+from oslo_utils import strutils
 from oslotest import base