Reserve migrations for DB backports

Reserve migrations in case we need to backport DB changes to the
stable/train branch.

Change-Id: Ie06276e221ee664f2862ba562c570c12192678cd

cinder/db/sqlalchemy/migrate_repo/versions/133_placeholder.py

@@ -0,0 +1,22 @@
+#    Licensed 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 KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+# This is a placeholder for Train backports.
+# Do not use this number for new Ussuri work. New work starts after all the
+# placeholders.
+#
+# See this for more information:
+# http://lists.openstack.org/pipermail/openstack-dev/2013-March/006827.html
+
+
+def upgrade(migrate_engine):
+    pass

cinder/db/sqlalchemy/migrate_repo/versions/134_placeholder.py

@@ -0,0 +1,22 @@
+#    Licensed 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 KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+# This is a placeholder for Train backports.
+# Do not use this number for new Ussuri work. New work starts after all the
+# placeholders.
+#
+# See this for more information:
+# http://lists.openstack.org/pipermail/openstack-dev/2013-March/006827.html
+
+
+def upgrade(migrate_engine):
+    pass

cinder/db/sqlalchemy/migrate_repo/versions/135_placeholder.py

@@ -0,0 +1,22 @@
+#    Licensed 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 KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+# This is a placeholder for Train backports.
+# Do not use this number for new Ussuri work. New work starts after all the
+# placeholders.
+#
+# See this for more information:
+# http://lists.openstack.org/pipermail/openstack-dev/2013-March/006827.html
+
+
+def upgrade(migrate_engine):
+    pass