webpack css-loader error 'Promise is not defined.' during jenkins build

Question

I know the Jenkins that I am running my code there, is using an old version on Node.js, but I don't have any permission to update it. Unfortunately updating Node.js is not a choice for me. I have done all the suggestion on github, stackoverflow, etc. but my code is still failing in Jenkins build. here is what I have added to the first lines of webpack.production.config.js:

require('es6-promise').polyfill();
require('es6-promise/auto');
var Promise = require('promise');

and here the added modules into package.json:

 "devDependencies": {
     ...
    "es6-promise": "^4.0.5",
    "promise" : "^7.1.1"
  }

but I am still getting the following error in jenkins build:

14:33:20 ERROR in ./~/css-loader!./~/less-loader!./style/cwa/global.less
14:33:20 Module build failed: ReferenceError: Promise is not defined
14:33:20     at LazyResult.async (/node_modules/css-loader/node_modules/postcss/lib/lazy-result.js:225:31)
14:33:20     at LazyResult.then (/node_modules/css-loader/node_modules/postcss/lib/lazy-result.js:131:21)
14:33:20     at processCss (/node_modules/css-loader/lib/processCss.js:199:5)
14:33:20     at Object.module.exports (/node_modules/css-loader/lib/loader.js:24:2)
14:33:20  @ ./style/cwa/global.less 4:14-123

14:33:20 ERROR in ./~/css-loader!./~/less-loader!./style/cwa/autosuggest.less
14:33:20 Module build failed: ReferenceError: Promise is not defined
14:33:20     at LazyResult.async (/node_modules/postcss/lib/lazy-result.js:225:31)
14:33:20     at LazyResult.then (/node_modules/css-loader/node_modules/postcss/lib/lazy-result.js:131:21)
14:33:20     at processCss (/node_modules/css-loader/lib/processCss.js:199:5)
14:33:20     at Object.module.exports (/node_modules/css-loader/lib/loader.js:24:2)
14:33:20  @ ./style/cwa/autosuggest.less 4:14-128

I really dont know what to do at this stage. if anybody knows, please help.