This has been updated to use Bootstrap Beta.2 (Latest stable) as of April. 12, 2018.
This also works with Angular 5, But not Angular 6. For Angular 6 you can use this post.
I'm aware that BS4 (non-beta) has been released, however there is a bug with ng5 cli and Bootstrap 4, so sticking with Beta.2 is your best bet for now. I'll update when the bug is fixed.
My picks for free project management applications 2018.