Remove oslo serialization requirement

Recently oslo serialization has started to also include
python-msgpack. Since we were only using it for json support, we
should just use python's json support. Especially since it's only
used by our tests.

Change-Id: I0f8d939d6fca7608eaa3eea7ea4ca93296aaab3a

openstackclient/tests/common/test_clientmanager.py

@@ -12,12 +12,13 @@
 #   License for the specific language governing permissions and limitations
 #   under the License.
 #
+
+import json as jsonutils
 import mock
 from requests_mock.contrib import fixture
 
 from keystoneclient.auth.identity import v2 as auth_v2
 from keystoneclient import service_catalog
-from oslo_serialization import jsonutils
 
 from openstackclient.api import auth
 from openstackclient.api import auth_plugin

requirements.txt

@@ -11,7 +11,6 @@ os-client-config
 oslo.config>=1.11.0  # Apache-2.0
 oslo.i18n>=1.5.0  # Apache-2.0
 oslo.utils>=1.4.0                       # Apache-2.0
-oslo.serialization>=1.4.0               # Apache-2.0
 python-glanceclient>=0.17.1
 python-keystoneclient>=1.3.0
 python-novaclient>=2.22.0