.env file to be used in production settings.

prod.env.js

module.exports = {
  NODE_ENV: '"production"',
  API_KEY: JSON.stringify(process.env.API_KEY) ,
  AUTH_DOMAIN: JSON.stringify(process.env.AUTH_DOMAIN) ,
  DATABASE_URL: JSON.stringify(process.env.DATABASE_URL) ,
  PROJECT_ID: JSON.stringify(process.env.PROJECT_ID) ,
  STORAGE_BUCKET: JSON.stringify(process.env.STORAGE_BUCKET) ,
  MESSENGER_SENDER_ID: JSON.stringify(process.env.MESSENGER_SENDER_ID)
}