Add migration code for existing deploy keys

db/migrate/20130506095501_remove_project_id_from_key.rb

 class RemoveProjectIdFromKey < ActiveRecord::Migration
   def up
+    puts 'Migrate deploy keys: '
+    Key.where('project_id IS NOT NULL').update_all(type: 'DeployKey')
+
+    DeployKey.all.each do |key|
+      project = Project.find_by_id(key.project_id)
+      if project
+        project.deploy_keys << key
+        print '.'
+      end
+    end
+
+    puts 'Done'
+
     remove_column :keys, :project_id
   end