message: Fix Context#sendBack type
diff: @@ -81,6 +81,8 @@ server.channel<UserParams, UserData, UserSubscribeAction>('user/:id', {
  type: 'user/rename',
  userId: ctx.data.user.id,
  name: ctx.data.user.name
  + }, {
  + status: 'processed'
  })
  }
  })
  