Fixes: qonos-manage doesn't run the scripts properly

- Alternative approach. Remove version_control from db_api and add it only by db_sync
- qonos-api start-up script updates the version for db migration to the latest before even the scripts are run.
- this patch fixes the problem and ensures that the migration scripts are run before the migration version is set to the latest.
Merge pull request #294 from venkateshsampath/rm/5422

Fixes: qonos-manage doesn't run the scripts properly