Fixing tests for new gametime tests

It appears that some mocks setup for gametime in the contrib
library were causing issues with the gametime tests. I've switched
those mocks to be patches instead so they are cleared out when
the test finishes.

evennia/utils/tests/test_gametime.py

@@ -5,6 +5,7 @@ Unit tests for the utilities of the evennia.utils.gametime module.
 import time
 from unittest.mock import Mock
 
+from django.conf import settings
 from django.test import TestCase
 
 from evennia.utils import gametime
@@ -13,12 +14,18 @@ time.time = Mock(return_value=1555595378.0)
 
 
 class TestGametime(TestCase):
-    def setUp(self):
+    def setUp(self) -> None:
         gametime.SERVER_RUNTIME = 600.0
         gametime.SERVER_START_TIME = time.time() - 300
         gametime.SERVER_RUNTIME_LAST_UPDATED = time.time() - 30
         gametime.TIMEFACTOR = 5.0
 
+    def tearDown(self) -> None:
+        gametime.SERVER_RUNTIME_LAST_UPDATED = 0.0
+        gametime.SERVER_RUNTIME = 0.0
+        gametime.SERVER_START_TIME = 0.0
+        gametime.TIMEFACTOR = settings.TIME_FACTOR
+
     def test_runtime(self):
         self.assertAlmostEqual(gametime.runtime(), 630.0)
 
@@ -69,6 +76,7 @@ class TestGametime(TestCase):
         self.assertIsInstance(script, gametime.TimeScript)
         self.assertAlmostEqual(script.interval, 17280)
         self.assertEqual(script.repeats, 1)
+        script.stop()
 
     def test_repeat_schedule(self):
         callback = Mock()
@@ -76,3 +84,4 @@ class TestGametime(TestCase):
         self.assertIsInstance(script, gametime.TimeScript)
         self.assertAlmostEqual(script.interval, 12)
         self.assertEqual(script.repeats, -1)
+        script.stop()