Use unittest.mock instead of third party mock

we currently don't support py2 and py3 has removed mock to
unittest module.

Change-Id: I5c13f6d2edc219957f5902227497aa24249ea74e

cliff/tests/test_app.py

@@ -21,8 +21,8 @@ except ImportError:
     from io import StringIO
 import sys
 
-import mock
 import six
+from unittest import mock
 
 from cliff import app as application
 from cliff import command as c_cmd

cliff/tests/test_command_hooks.py

@@ -18,8 +18,8 @@ from cliff import lister
 from cliff import show
 from cliff.tests import base
 
-import mock
 from stevedore import extension
+from unittest import mock
 
 
 def make_app(**kwargs):

cliff/tests/test_commandmanager.py

@@ -10,8 +10,8 @@
 #  License for the specific language governing permissions and limitations
 #  under the License.
 
-import mock
 import testscenarios
+from unittest import mock
 
 from cliff import command
 from cliff import commandmanager

cliff/tests/test_complete.py

@@ -13,7 +13,7 @@
 """Bash completion tests
 """
 
-import mock
+from unittest import mock
 
 from cliff import app as application
 from cliff import commandmanager

cliff/tests/test_formatters_csv.py

@@ -16,8 +16,8 @@
 import argparse
 import unittest
 
-import mock
 import six
+from unittest import mock
 
 from cliff.formatters import commaseparated
 from cliff.tests import test_columns

cliff/tests/test_formatters_json.py

@@ -18,8 +18,8 @@ from cliff.formatters import json_format
 from cliff.tests import base
 from cliff.tests import test_columns
 
-import mock
 import six
+from unittest import mock
 
 
 class TestJSONFormatter(base.TestBase):

cliff/tests/test_formatters_shell.py

@@ -15,12 +15,12 @@
 import argparse
 import six
 
+from unittest import mock
+
 from cliff.formatters import shell
 from cliff.tests import base
 from cliff.tests import test_columns
 
-import mock
-
 
 class TestShellFormatter(base.TestBase):
 

cliff/tests/test_formatters_table.py

@@ -16,8 +16,8 @@ import argparse
 import os
 import textwrap
 
-import mock
 from six import StringIO
+from unittest import mock
 
 from cliff.formatters import table
 from cliff.tests import base

cliff/tests/test_formatters_yaml.py

@@ -15,12 +15,12 @@
 import six
 import yaml
 
+from unittest import mock
+
 from cliff.formatters import yaml_format
 from cliff.tests import base
 from cliff.tests import test_columns
 
-import mock
-
 
 class TestYAMLFormatter(base.TestBase):
 

cliff/tests/test_help.py

@@ -17,7 +17,7 @@ except ImportError:
 import os
 import sys
 
-import mock
+from unittest import mock
 
 from cliff import app as application
 from cliff import commandmanager

cliff/tests/test_lister.py

@@ -14,11 +14,11 @@
 
 import weakref
 
+from unittest import mock
+
 from cliff import lister
 from cliff.tests import base
 
-import mock
-
 
 class FauxFormatter(object):
 

cliff/tests/test_show.py

@@ -14,11 +14,11 @@
 
 import weakref
 
+from unittest import mock
+
 from cliff import show
 from cliff.tests import base
 
-import mock
-
 
 class FauxFormatter(object):
 

cliff/tests/test_utils.py

@@ -17,7 +17,7 @@ import struct
 import sys
 import unittest
 
-import mock
+from unittest import mock
 
 from cliff import utils
 from cliff.tests import base