build: fix snapshot build package.json substitution
build: fix snapshot build package.json substitution

This was relying on undocumented behaviour in copy_to_directory which
now needs to be enabled with a flag.

clydin/angular-cli,angular/angular-cli,angular/angular-cli,angular/angular-cli,clydin/angular-cli,angular/angular-cli,clydin/angular-cli,clydin/angular-cli