Decorate one configuration object with values from another.

@param  {Object} object  An existing config object.
@param  {Object} values  An overriding config object.
function decorate (object, values) {
  for (var key in values) {
    if (typeof object[key] === 'object') {
      decorate(object[key], values[key])
    } else {
      object[key] = values[key]
    }
  }
}