old_contents: module.exports={
    rateLimit: process.env.RATELIMIT,
    port: process.env.PORT,
    log: true
  }
  
new_contents: module.exports={
    rateLimit: process.env.RATELIMIT || 10,
    port: process.env.PORT || 5000,
    log: true
  }
  
subject: add defaults