Unable to rollback migration

[karenc]

We initiated the schema migration database with --context cnx-archive --context cnx-publishing. If we use only --context cnx-publishing, dbmigrator can't rollback the migration:

karen@trusty:~/db-migrator (logger)$ dbmigrator --context cnx-publishing --config ~/cnx-publishing/development.ini list
name                      | is applied | date applied
----------------------------------------------------------------------
20160104115058_add_api_ke   True         2016-02-26 09:00:51.709179+01:00

karen@trusty:~/db-migrator (logger)$ dbmigrator --context cnx-publishing --config ~/cnx-publishing/development.ini rollback
No migrations to roll back.

Is it a bug...?