Enum mappings are now exposed via class methods instead of constants.

Example:

    class Conversation < ActiveRecord::Base
      enum status: [ :active, :archived ]
    end

Before:

    Conversation::STATUS # => { "active" => 0, "archived" => 1 }

After:

    Conversation.statuses # => { "active" => 0, "archived" => 1 }
Active Record's subclass_from_attributes shouldn't assume :type is for STI unless there is a type column.