rosa-build/db/migrate/20120321130436_add_devise_lockable.rb

class AddDeviseLockable < ActiveRecord::Migration
  def change
    add_column :users, :failed_attempts, :integer, default: 0 # Only if lock strategy is :failed_attempts
    add_column :users, :unlock_token, :string # Only if unlock strategy is :email or :both
    add_column :users, :locked_at, :datetime
    add_index :users, :unlock_token,         unique: true
  end
end