Why do we need ng-packagr?

[scaleit]

It has a lot of vulnerabilities and I think the latest version will brake our code as Ionic 3 works with Angular <6.

                     === npm audit security report ===                        
                                                                               
# Run  npm install --save-dev ng-packagr@4.2.0  to resolve 36 vulnerabilities
SEMVER WARNING: Recommended action is a potentially breaking change

[frostyandy2k]

v4 of ng-packagr will break our code!
This is blocked by #27