LGTM fixes - not calling super on Finder subclasses

Author: dantownsend

piccolo/apps/migrations/commands/backwards.py

@@ -9,6 +9,7 @@ class BackwardsMigrationManager(BaseMigrationManager):
     def __init__(self, app_name: str, migration_id: str):
         self.migration_id = migration_id
         self.app_name = app_name
+        super().__init__()
 
     def run(self):
         app_modules = self.get_app_modules()

piccolo/apps/migrations/commands/check.py

@@ -6,6 +6,7 @@
 class CheckMigrationManager(BaseMigrationManager):
     def __init__(self, app_name: str):
         self.app_name = app_name
+        super().__init__()
 
     def run(self):
         print("Listing migrations ...")

piccolo/apps/migrations/commands/forwards.py

@@ -22,6 +22,7 @@ def __init__(
         self.app_name = app_name
         self.migration_id = migration_id
         self.fake = fake
+        super().__init__()
 
     def run_migrations(self, app_config: AppConfig) -> None:
         already_ran = Migration.get_migrations_which_ran(