Ensure migration file names are unique to avoid caching errors
Ensure migration file names are unique to avoid caching errors

This patch requires migration files to include a prefix (expand,
migrate, contract) in order to keep them unique and prevent a bug
related to caching. Here is the standard format:
[version]_[prefix]_[description]

For example:
* 001_expand_new_fk_constraint.py
* 001_migrate_new_fk_constraint.py
* 001_contract_new_fk_constraint.py

Closes-Bug: #1658116
Change-Id: I3431381abfe4d9fd15512c5c7beb6ab0028dc38e

mahak/keystone,mahak/keystone,rajalokan/keystone,ilay09/keystone,rajalokan/keystone,openstack/keystone,ilay09/keystone,openstack/keystone,mahak/keystone,rajalokan/keystone,openstack/keystone,ilay09/keystone