[Part7] Remove six

We don't need this in a Python 3-only world.

Remove six in follows:
1. zaqar/transport/base.py
2. zaqar/transport/middleware/cors.py
3. zaqar/transport/middleware/profile.py
4. zaqar/transport/validation.py
5. zaqar/transport/wsgi/driver.py

Change-Id: I0cd64879265f8657322d02f7e9048ed338fe2cf7

zaqar/transport/base.py

@@ -15,8 +15,6 @@
 
 import abc
 
-import six
-
 from zaqar.conf import default
 from zaqar.conf import transport
 
@@ -47,8 +45,7 @@ class ResourceDefaults(object):
         return self._defaults.default_subscription_ttl
 
 
-@six.add_metaclass(abc.ABCMeta)
-class DriverBase(object):
+class DriverBase(object, metaclass=abc.ABCMeta):
     """Base class for Transport Drivers to document the expected interface.
 
     :param conf: configuration instance

zaqar/transport/middleware/cors.py

@@ -12,7 +12,7 @@
 #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 #    License for the specific language governing permissions and limitations
 #    under the License.
-import six.moves.urllib.parse as urlparse
+from urllib import parse as urlparse
 import webob
 
 from oslo_log import log

zaqar/transport/middleware/profile.py

@@ -13,7 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import six.moves.urllib.parse as urlparse
+from urllib import parse as urlparse
 import webob
 
 from oslo_log import log

zaqar/transport/validation.py

@@ -19,7 +19,7 @@ import re
 import uuid
 
 from oslo_utils import timeutils
-import six
+from urllib import parse as urllib_parse
 
 from zaqar.common import consts
 from zaqar.conf import transport
@@ -569,7 +569,7 @@ class Validator(object):
         subscriber_type = None
 
         if subscriber:
-            parsed_uri = six.moves.urllib_parse.urlparse(subscriber)
+            parsed_uri = urllib_parse.urlparse(subscriber)
             subscriber_type = parsed_uri.scheme
 
             if subscriber_type not in self._limits_conf.subscriber_types:

zaqar/transport/wsgi/driver.py

@@ -15,7 +15,6 @@
 
 from distutils import version as d_version
 import falcon
-import six
 import socket
 from wsgiref import simple_server
 
@@ -169,7 +168,7 @@ class Driver(transport.DriverBase):
             raise
         LOG.exception('Internal server error')
         raise falcon.HTTPInternalServerError('Internal server error',
-                                             six.text_type(exc))
+                                             str(exc))
 
     def _get_server_cls(self, host):
         """Return an appropriate WSGI server class base on provided host