prefer newer unittest.mock when available

tests/test_datacontainer.py

@@ -3,12 +3,15 @@
 """
 import configobj
 import pytest
-import mock
 import unittest
 import time
 try: import simplejson as json
 except ImportError: import json
 import socket
+try:
+    from unittest import mock
+except ImportError:
+    import mock
 
 import sys
 import os

tests/test_memory_leak.py

@@ -3,8 +3,11 @@
 """
 import configobj
 import pytest
-import mock
 import unittest
+try:
+    from unittest import mock
+except ImportError:
+    import mock
 
 import resource
 import sys

tests/test_sampleprobe.py

@@ -3,9 +3,12 @@
 """
 import configobj
 import pytest
-import mock
 import unittest
 import socket
+try:
+    from unittest import mock
+except ImportError:
+    import mock
 
 import resource
 import time

tests/test_senderprotocol.py

@@ -3,12 +3,15 @@
 """
 import configobj
 import pytest
-import mock
 import unittest
 import time
 try: import simplejson as json
 except ImportError: import json
 import socket
+try:
+    from unittest import mock
+except ImportError:
+    import mock
 
 import sys
 import os

tests/test_zabbixagentconfig.py

@@ -3,9 +3,12 @@
 """
 import configobj
 import pytest
-import mock
 import unittest
 import logging
+try:
+    from unittest import mock
+except ImportError:
+    import mock
 
 import sys
 import os