Replace mock with unittest.mock

One less dependency to worry about.

Signed-off-by: Stephen Finucane <stephen@that.guru>

Author: stephenfin

test-requirements.txt

@@ -1,3 +1,2 @@
-mock~=3.0.0
 pytest>=3.0,<6.0
 pytest-cov~=2.5

tests/test_api.py

@@ -1,6 +1,7 @@
 """Unit tests for ``git_pw/api.py``."""
 
-import mock
+from unittest import mock
+
 import pytest
 
 from git_pw import api

tests/test_bundle.py

@@ -1,7 +1,7 @@
 import unittest
+from unittest import mock
 
 from click.testing import CliRunner as CLIRunner
-import mock
 
 from git_pw import bundle
 

tests/test_patch.py

@@ -1,8 +1,8 @@
 import unittest
+from unittest import mock
 
 import click
 from click.testing import CliRunner as CLIRunner
-import mock
 from packaging import version
 
 from git_pw import patch

tests/test_series.py

@@ -1,7 +1,7 @@
 import unittest
+from unittest import mock
 
 from click.testing import CliRunner as CLIRunner
-import mock
 
 from git_pw import series
 

tests/test_utils.py

@@ -6,8 +6,8 @@
 import textwrap
 import os
 
-import mock
 import yaml
+from unittest import mock
 
 from git_pw import utils