*   Add `config.active_model.i18n_full_message` in order to control whether
    the `full_message` error format can be overridden at the attribute or model
    level in the locale files. This is `false` by default.

    *Martin Larochelle*

*   Rails 6 requires Ruby 2.4.1 or newer.

    *Jeremy Daer*


Please check [5-2-stable](https://github.com/rails/rails/blob/5-2-stable/activemodel/CHANGELOG.md) for previous changes.