Fix watcher audit list command

This patch set adds data migration version that fills noname audits
with name like strategy.name + '-' + audit.created_at.

Closes-Bug: #1738758
Change-Id: I1d65b3110166e9f64ce5b80a34672d24d629807d

watcher/db/sqlalchemy/alembic/versions/a86240e89a29_.py

@@ -0,0 +1,34 @@
+"""Set name for Audit as part of backward compatibility
+
+Revision ID: a86240e89a29
+Revises: 3cfc94cecf4e
+Create Date: 2017-12-21 13:00:09.278587
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = 'a86240e89a29'
+down_revision = '3cfc94cecf4e'
+
+from alembic import op
+from sqlalchemy.orm import sessionmaker
+from watcher.db.sqlalchemy import models
+
+
+def upgrade():
+    connection = op.get_bind()
+    session = sessionmaker()
+    s = session(bind=connection)
+    for audit in s.query(models.Audit).filter(models.Audit.name is None).all():
+        strategy_name = s.query(models.Strategy).filter_by(id=audit.strategy_id).one().name
+        audit.update({'name': strategy_name + '-' + str(audit.created_at)})
+    s.commit()
+
+
+def downgrade():
+    connection = op.get_bind()
+    session = sessionmaker()
+    s = session(bind=connection)
+    for audit in s.query(models.Audit).filter(models.Audit.name is not None).all():
+        audit.update({'name': None})
+    s.commit()