Addon Manager: pylint cleanup in startup workers

src/Mod/AddonManager/AddonManagerTest/gui/test_workers_startup.py

@@ -154,4 +154,13 @@ class TestWorkersStartup(unittest.TestCase):
     def _macro_added_from_cache(self, addon:Addon):
         """ Callback for adding macros from the cache """
         print (f"Macro Cache Test: {addon.name}")
-        self.macro_from_cache_counter += 1
+        self.macro_from_cache_counter += 1
+
+    def test_update_checker(self):
+        """ Test the code that checks a single addon for available updates. """
+
+        # First, install a specific Addon of each kind
+
+        # Arrange for those addons to be out-of-date
+
+        # Check for updates