[AIRFLOW-XXX] Update Alembic autogenerator to pass pylint (#6216)

airflow/migrations/env.py

@@ -17,9 +17,10 @@
 # specific language governing permissions and limitations
 # under the License.
 
-from alembic import context
 from logging.config import fileConfig
 
+from alembic import context
+
 from airflow import settings
 from airflow import models
 

airflow/migrations/script.py.mako

@@ -6,9 +6,9 @@
 # to you under the Apache License, Version 2.0 (the
 # "License"); you may not use this file except in compliance
 # with the License.  You may obtain a copy of the License at
-# 
+#
 #   http://www.apache.org/licenses/LICENSE-2.0
-# 
+#
 # Unless required by applicable law or agreed to in writing,
 # software distributed under the License is distributed on an
 # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
@@ -24,19 +24,22 @@ Create Date: ${create_date}
 
 """
 
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
 # revision identifiers, used by Alembic.
 revision = ${repr(up_revision)}
 down_revision = ${repr(down_revision)}
 branch_labels = ${repr(branch_labels)}
 depends_on = ${repr(depends_on)}
 
-from alembic import op
-import sqlalchemy as sa
-${imports if imports else ""}
 
 def upgrade():
+    """Apply ${message}"""
     ${upgrades if upgrades else "pass"}
 
 
 def downgrade():
+    """Unapply ${message}"""
     ${downgrades if downgrades else "pass"}