Angular v8 support

[beyondtheobservableuniverse]

Please update project to Angular version 8.

[s4m0r4m4]

Angular v9 is out too now.

[dtomasbar]

And so are 10 and 11

[Sampath-Lokuge]

Now it is 12+

[Sampath-Lokuge]

Hmm.. it seems no more this library. I have moved to this: https://github.com/valor-software/ng2-charts

[Rlcolli4]

We use both @Sampath-Lokuge recommended ng2-charts and this in our application. Currently in Angular 13 angular2-chartjs gives a warning but still works. ng2-charts has given us no equivalent warning or errors in Angular 13. Hopefully the maintainers of this project can fix the warning soon otherwise we too will fully migrate to ng2-charts as well.