use newer unittest.mock everwhere

gensim/corpora/sharded_corpus.py

@@ -17,8 +17,6 @@
 
 """
 
-from __future__ import print_function
-
 import logging
 import os
 import math

gensim/test/test_parsing.py

@@ -7,8 +7,8 @@
 
 import logging
 import unittest
+from unittest import mock
 
-import mock
 import numpy as np
 
 from gensim.parsing.preprocessing import (

gensim/test/test_poincare.py

@@ -13,10 +13,7 @@
 import os
 import tempfile
 import unittest
-try:
-    from mock import Mock
-except ImportError:
-    from unittest.mock import Mock
+from unittest.mock import Mock
 
 import numpy as np
 try:

gensim/utils.py

@@ -6,7 +6,6 @@
 
 """Various general utility functions."""
 
-from __future__ import with_statement
 from contextlib import contextmanager
 import collections.abc
 import logging

setup.py

@@ -272,7 +272,6 @@ def run(self):
 core_testenv = [
     'pytest',
     'pytest-cov',
-    'mock',
     'testfixtures',
 ]