use unittest.mock instead of mock where possible

[pgajdos]

Could you please allow to drop python-mock dependency if not needed? Following works for 3.8, 3.9 and 3.10 but obviously will not be usable for Python 2.

diff -upr python-smpplib-2.2.1.orig/smpplib/tests/test_client.py python-smpplib-2.2.1/smpplib/tests/test_client.py
--- python-smpplib-2.2.1.orig/smpplib/tests/test_client.py	2022-05-04 09:38:34.127959320 +0200
+++ python-smpplib-2.2.1/smpplib/tests/test_client.py	2022-05-04 09:38:34.147959444 +0200
@@ -1,6 +1,6 @@
 import warnings
 import pytest
-from mock import Mock, call
+from unittest.mock import Mock, call
 
 from smpplib.client import Client
 from smpplib.smpp import make_pdu
diff -upr python-smpplib-2.2.1.orig/smpplib/tests/test_gsm.py python-smpplib-2.2.1/smpplib/tests/test_gsm.py
--- python-smpplib-2.2.1.orig/smpplib/tests/test_gsm.py	2022-05-04 09:38:34.127959320 +0200
+++ python-smpplib-2.2.1/smpplib/tests/test_gsm.py	2022-05-04 09:38:34.147959444 +0200
@@ -1,6 +1,6 @@
 # -*- coding: utf8 -*-
 
-import mock
+from unittest import mock
 from pytest import mark, raises
 
 from smpplib import consts

[pgajdos]

See:
https://trello.com/c/S6eADbii/64-remove-python-mock
https://fedoraproject.org/wiki/Changes/DeprecatePythonMock