Reserve 10 migrations for backports

Reserve 10 migrations so that we have the option of backporting fixes
that include a db migration to the stable/havana branch.  We did this
same thing to allow backports to stable/grizzly in
b52a215.

The choice of 10 migrations is just a magic number.  We haven't used any
of the 10 reserved for stable/grizzly backports, so 10 seems to be
enough.

Implements blueprint backportable-db-migrations-icehouse

Change-Id: I2c5f2e5a966cfffa4a3e54e17fde07a52295f658

nova/db/sqlalchemy/migrate_repo/versions/217_placeholder.py

@@ -0,0 +1,14 @@
+# This is a placeholder for Havana backports.
+# Do not use this number for new Icehouse work.  New Icehouse work starts after
+# all the placeholders.
+#
+# See blueprint backportable-db-migrations-icehouse
+# http://lists.openstack.org/pipermail/openstack-dev/2013-March/006827.html
+
+
+def upgrade(migrate_engine):
+    pass
+
+
+def downgrade(migration_engine):
+    pass

nova/db/sqlalchemy/migrate_repo/versions/218_placeholder.py

@@ -0,0 +1,14 @@
+# This is a placeholder for Havana backports.
+# Do not use this number for new Icehouse work.  New Icehouse work starts after
+# all the placeholders.
+#
+# See blueprint backportable-db-migrations-icehouse
+# http://lists.openstack.org/pipermail/openstack-dev/2013-March/006827.html
+
+
+def upgrade(migrate_engine):
+    pass
+
+
+def downgrade(migration_engine):
+    pass

nova/db/sqlalchemy/migrate_repo/versions/219_placeholder.py

@@ -0,0 +1,14 @@
+# This is a placeholder for Havana backports.
+# Do not use this number for new Icehouse work.  New Icehouse work starts after
+# all the placeholders.
+#
+# See blueprint backportable-db-migrations-icehouse
+# http://lists.openstack.org/pipermail/openstack-dev/2013-March/006827.html
+
+
+def upgrade(migrate_engine):
+    pass
+
+
+def downgrade(migration_engine):
+    pass

nova/db/sqlalchemy/migrate_repo/versions/220_placeholder.py

@@ -0,0 +1,14 @@
+# This is a placeholder for Havana backports.
+# Do not use this number for new Icehouse work.  New Icehouse work starts after
+# all the placeholders.
+#
+# See blueprint backportable-db-migrations-icehouse
+# http://lists.openstack.org/pipermail/openstack-dev/2013-March/006827.html
+
+
+def upgrade(migrate_engine):
+    pass
+
+
+def downgrade(migration_engine):
+    pass

nova/db/sqlalchemy/migrate_repo/versions/221_placeholder.py

@@ -0,0 +1,14 @@
+# This is a placeholder for Havana backports.
+# Do not use this number for new Icehouse work.  New Icehouse work starts after
+# all the placeholders.
+#
+# See blueprint backportable-db-migrations-icehouse
+# http://lists.openstack.org/pipermail/openstack-dev/2013-March/006827.html
+
+
+def upgrade(migrate_engine):
+    pass
+
+
+def downgrade(migration_engine):
+    pass

nova/db/sqlalchemy/migrate_repo/versions/222_placeholder.py

@@ -0,0 +1,14 @@
+# This is a placeholder for Havana backports.
+# Do not use this number for new Icehouse work.  New Icehouse work starts after
+# all the placeholders.
+#
+# See blueprint backportable-db-migrations-icehouse
+# http://lists.openstack.org/pipermail/openstack-dev/2013-March/006827.html
+
+
+def upgrade(migrate_engine):
+    pass
+
+
+def downgrade(migration_engine):
+    pass

nova/db/sqlalchemy/migrate_repo/versions/223_placeholder.py

@@ -0,0 +1,14 @@
+# This is a placeholder for Havana backports.
+# Do not use this number for new Icehouse work.  New Icehouse work starts after
+# all the placeholders.
+#
+# See blueprint backportable-db-migrations-icehouse
+# http://lists.openstack.org/pipermail/openstack-dev/2013-March/006827.html
+
+
+def upgrade(migrate_engine):
+    pass
+
+
+def downgrade(migration_engine):
+    pass

nova/db/sqlalchemy/migrate_repo/versions/224_placeholder.py

@@ -0,0 +1,14 @@
+# This is a placeholder for Havana backports.
+# Do not use this number for new Icehouse work.  New Icehouse work starts after
+# all the placeholders.
+#
+# See blueprint backportable-db-migrations-icehouse
+# http://lists.openstack.org/pipermail/openstack-dev/2013-March/006827.html
+
+
+def upgrade(migrate_engine):
+    pass
+
+
+def downgrade(migration_engine):
+    pass

nova/db/sqlalchemy/migrate_repo/versions/225_placeholder.py

@@ -0,0 +1,14 @@
+# This is a placeholder for Havana backports.
+# Do not use this number for new Icehouse work.  New Icehouse work starts after
+# all the placeholders.
+#
+# See blueprint backportable-db-migrations-icehouse
+# http://lists.openstack.org/pipermail/openstack-dev/2013-March/006827.html
+
+
+def upgrade(migrate_engine):
+    pass
+
+
+def downgrade(migration_engine):
+    pass

nova/db/sqlalchemy/migrate_repo/versions/226_placeholder.py

@@ -0,0 +1,14 @@
+# This is a placeholder for Havana backports.
+# Do not use this number for new Icehouse work.  New Icehouse work starts after
+# all the placeholders.
+#
+# See blueprint backportable-db-migrations-icehouse
+# http://lists.openstack.org/pipermail/openstack-dev/2013-March/006827.html
+
+
+def upgrade(migrate_engine):
+    pass
+
+
+def downgrade(migration_engine):
+    pass