update remaining code for versioned config

migrations/021-config-version-id.js

@@ -3,6 +3,7 @@ var db = require('./db')
 exports.up = function (next) {
   var sql = [
     'alter table devices add column user_config_id int',
+    'alter table user_config add column created timestamptz NOT NULL default now()',
     `ALTER TABLE devices ADD CONSTRAINT user_config_id
     FOREIGN KEY (user_config_id)
     REFERENCES user_config (id)`