Merge "Deprecate branchless migration chains from neutron-db-manage"

diff --cc neutron/db/migration/cli.py
index e58c00518cb83e48f58591eed76ab5591051379e,5f775fc04df5720e0f0ef928b6f797a695d72e7f..d2edc9d54e8d2e02c89f9486964087e559e0bc3b
--- 1/neutron/db/migration/cli.py
--- 2/neutron/db/migration/cli.py
+++ b/neutron/db/migration/cli.py
@@@ -24,9 -24,9 +24,10 @@@ from oslo_config import cf
  from oslo_utils import fileutils
  from oslo_utils import importutils
  import pkg_resources
+ import six
  
  from neutron.common import utils
 +from neutron.db import migration
  
  
  HEAD_FILENAME = 'HEAD'