docs: add more info to test tools (old and new) [Skip CI]

`versionadded` annotation for new stuff in `sopel.tests` namespace.

Note in `sopel.test_tools` docstring that the (unlisted) mock classes
within are deprecated, and link to the new tools.

sopel/test_tools.py

@@ -1,5 +1,14 @@
 # coding=utf-8
-"""This module has classes and functions that can help in writing tests."""
+"""This module has classes and functions that can help in writing tests.
+
+.. note::
+
+   This module formerly contained mock classes for bot, bot wrapper, and config
+   objects. Those are deprecated, and will be removed in Sopel 8.0. New code
+   should use the new :mod:`.mocks`, :mod:`.factories`, and
+   :mod:`.pytest_plugin` added in Sopel 7.0.
+
+"""
 # Copyright 2013, Ari Koivula, <ari@koivu.la>
 # Copyright 2019, Florian Strzelecki <florian.strzelecki@gmail.com>
 # Licensed under the Eiffel Forum License 2.

sopel/tests/__init__.py

@@ -1,5 +1,8 @@
 # coding=utf-8
-"""Tests tools, factories, pytest fixtures, and mocks."""
+"""Test tools, factories, pytest fixtures, and mocks.
+
+.. versionadded:: 7.0
+"""
 from __future__ import unicode_literals, absolute_import, print_function, division
 
 

sopel/tests/factories.py

@@ -1,5 +1,8 @@
 # coding=utf-8
-"""Test factories: they create objects for testing purposes."""
+"""Test factories: they create objects for testing purposes.
+
+.. versionadded:: 7.0
+"""
 from __future__ import unicode_literals, absolute_import, print_function, division
 
 import re

sopel/tests/mocks.py

@@ -1,5 +1,8 @@
 # coding=utf-8
-"""Test mocks: they fake objects for testing."""
+"""Test mocks: they fake objects for testing.
+
+.. versionadded:: 7.0
+"""
 from __future__ import unicode_literals, absolute_import, print_function, division
 
 

sopel/tests/pytest_plugin.py

@@ -1,5 +1,8 @@
 # coding=utf-8
-"""Pytest plugin for Sopel."""
+"""Pytest plugin for Sopel.
+
+.. versionadded:: 7.0
+"""
 from __future__ import unicode_literals, absolute_import, print_function, division
 
 import pytest