sqlalchemy: Use built-in declarative

sqlalchemy.ext.declarative was deprecated in sqlalchemy 1.4.0, due to
the built-in implementations[1].

[1] https://github.com/sqlalchemy/sqlalchemy/commit/450f5c0d6519a439f40

Change-Id: Ia8c2ed6836a6ecaa1d947382d3ad912f2fd4d17f
Signed-off-by: Takashi Kajinami <kajinamit@oss.nttdata.com>

requirements.txt

@@ -26,7 +26,7 @@ Werkzeug>=0.14.1 # BSD License
 keystonemiddleware>=4.21.0 # Apache-2.0
 stevedore>=1.28.0 # Apache-2.0
 voluptuous>=0.11.1 # BSD License
-SQLAlchemy>=1.2.5 # MIT
+SQLAlchemy>=1.4.0 # MIT
 sympy>=1.1.1 # BSD
 pysnmp>=7.1.0  # BSD
 PyJWT>=1.6.0 # MIT

vitrage/storage/sqlalchemy/models.py

@@ -19,7 +19,7 @@ from oslo_db.sqlalchemy import models
 
 from sqlalchemy import Column, DateTime, INTEGER, String, \
     SmallInteger, BigInteger, Index, Boolean, ForeignKey
-from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import declarative_base
 from sqlalchemy.orm import relationship
 import sqlalchemy.types as types