Use built-in unittest.mock instead of third-party mock

Python 3 has a built-in version of mock available as unittest.mock.
Use it instead of installing the third-party package.

Author: mgorny

requirements.txt

@@ -2,12 +2,10 @@ bumpversion
 click
 flake8>=2.2.3
 ipython
-mock
 pytest-cov
 pytest>=3.9
 sh>=1.09
 tox
-types-mock
 wheel
 twine
 portray

tests/test_ipython.py

@@ -1,6 +1,5 @@
 import os
-
-import mock
+from unittest import mock
 
 import pytest
 

tests/test_main.py

@@ -3,8 +3,8 @@
 import os
 import sys
 import textwrap
+from unittest import mock
 
-import mock
 import pytest
 import sh
 

tox.ini

@@ -14,7 +14,6 @@ python =
 
 [testenv]
 deps =
-  mock
   pytest
   coverage
   sh
@@ -27,7 +26,6 @@ skip_install = true
 deps =
   flake8
   mypy
-  types-mock
 commands =
   flake8 src tests
   mypy --python-version=3.11 src tests