Merge ~afreiberger/charm-graylog:blacken-20.10 into charm-graylog:master

[Drew Freiberger]

[Alvaro Uria (aluria)]

lgtm

review: Approve

diff --git a/src/tests/functional/tests/test_graylog_upgrade.py b/src/tests/functional/tests/test_graylog_upgrade.py
index 2160414..ed6358d 100644
--- a/src/tests/functional/tests/test_graylog_upgrade.py
+++ b/src/tests/functional/tests/test_graylog_upgrade.py
@@ -146,7 +146,9 @@ class UpgradeTest(unittest.TestCase):
         model.set_application_config("graylog", {"channel": "fake"})
         for unit_name in self.unit_names:
             self._block_until(
-                unit_name, "blocked", "Invalid snap channel: fake",
+                unit_name,
+                "blocked",
+                "Invalid snap channel: fake",
             )
 
         # Roll back