Use six.text_type instead of unicode

unicode type renamed in Python 3.x. We need to use
six.text_type to get code works with both Python 2.7 and 3.x

Related-Bug: #1380806

Change-Id: Ia26a29fab377b61ce4abf81f3eb778988eb8b893

os_brick/exception.py

@@ -14,6 +14,8 @@
 
 """Exceptions for the Brick library."""
 
+import six
+
 from os_brick.i18n import _, _LE
 from os_brick.openstack.common import log as logging
 
@@ -64,7 +66,7 @@ class BrickException(Exception):
         super(BrickException, self).__init__(message)
 
     def __unicode__(self):
-        return unicode(self.msg)
+        return six.text_type(self.msg)
 
 
 class NotFound(BrickException):

os_brick/tests/initiator/test_connector.py

@@ -20,6 +20,7 @@ import time
 
 import mock
 from oslo_concurrency import processutils as putils
+import six
 import testtools
 
 from os_brick import exception
@@ -722,7 +723,7 @@ class FibreChannelConnectorTestCase(ConnectorTestCase):
         name = 'volume-00000001'
         vol = {'id': 1, 'name': name}
         # Should work for string, unicode, and list
-        wwns = ['1234567890123456', unicode('1234567890123456'),
+        wwns = ['1234567890123456', six.text_type('1234567890123456'),
                 ['1234567890123456', '1234567890123457']]
         for wwn in wwns:
             connection_info = self.fibrechan_connection(vol, location, wwn)

os_brick/tests/test_exception.py

@@ -15,6 +15,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import six
+
 from os_brick import exception
 from os_brick.tests import base
 
@@ -25,24 +27,26 @@ class BrickExceptionTestCase(base.TestCase):
             message = "default message"
 
         exc = FakeBrickException()
-        self.assertEqual(unicode(exc), 'default message')
+        self.assertEqual(six.text_type(exc), 'default message')
 
     def test_error_msg(self):
-        self.assertEqual(unicode(exception.BrickException('test')), 'test')
+        self.assertEqual(six.text_type(exception.BrickException('test')),
+                         'test')
 
     def test_default_error_msg_with_kwargs(self):
         class FakeBrickException(exception.BrickException):
             message = "default message: %(code)s"
 
         exc = FakeBrickException(code=500)
-        self.assertEqual(unicode(exc), 'default message: 500')
+        self.assertEqual(six.text_type(exc), 'default message: 500')
 
     def test_error_msg_exception_with_kwargs(self):
         class FakeBrickException(exception.BrickException):
             message = "default message: %(mispelled_code)s"
 
         exc = FakeBrickException(code=500)
-        self.assertEqual(unicode(exc), 'default message: %(mispelled_code)s')
+        self.assertEqual(six.text_type(exc),
+                         'default message: %(mispelled_code)s')
 
     def test_default_error_code(self):
         class FakeBrickException(exception.BrickException):