SQL schema scripts are replaced with Alembic command line tool.
Notification plugins are enabled in notification engine configuration
file.
The change also fixes the `sub_alarm` table schema. The foreign key must
refer to the field with the same data type, charset and collation.
Otherwise the schema migration fails occasionally with Python 3 with the
IntegrityError[1]:
oslo_db.exception.DBError: (pymysql.err.IntegrityError) (1215, 'Cannot add foreign key constraint')
[1] http://logs.openstack.org/61/622361/8/gate/monasca-tempest-python3-influxdb/26104a3/controller/logs/devstacklog.txt.gz#_2019-01-30_15_52_45_455
Change-Id: I95d7e91e62ff13e84f963fdbb3bca6b7dfd7c310
Story: 2001654
Task: 14421
6409d06439