How do manage staging and prod configurations?

[ir-fuel]

Since all the deployment info is inside package.json, how can I manage a staging and a production build of my app without duplicating everything? The url's for the autoupdater are different, so is the icon, the appId and the productName.

How can I duplicate the 'build' section without duplicating my entire package.json?

[develar]

Duplicates #639