message: Fix: properly detect direct_message event
  The method for detecting this was incorrect.
diff: @@ -260,7 +260,7 @@ function Sparkbot(configuration) {
  if (message.type == 'message_received') {
  if (message.user === controller.identity.emails[0]) {
  message.type = 'self_message';
  - } else if (message.raw_message.roomType == 'direct') {
  + } else if (message.raw_message.data.roomType == 'direct') {
  message.type = 'direct_message';
  } else {
  message.type = 'direct_mention';
  