How to Fix Build Fail in ionic Pro

Hi everyone,
I’m running into this issue https://github.com/jf3096/json-typescript-mapper/issues/11 when building my app in ionicPro.

I could solve it when building locally by applying wallacemv tip

C:\xxx\node_modules\json-typescript-mapper>uglifyjs lib/utils.js -o utils.js --source-map utils.map.js
will generate utils.js and utils.map.js in json-typescript-mapper folder… copy these files into lib folder @clarkmcnally

But how to copy utils.js and utils.map.js files into lib folder when building under ionic Pro ?

Thank you for your help,
E.G