This cop will analyze migrations that add columns with string, and report an offense if the string has no limit enforced Related to https://gitlab.com/gitlab-org/gitlab-ce/issues/64505
This new attribute is optional and used when set instead of the default format `gitlab+deploy-token-#{id}`. Empty usernames will be saved as null in the database. Related to https://gitlab.com/gitlab-org/gitlab-ce/issues/50228.