v8.0.2

what I didnt like in versions 6 and lower was that SceneBase.addChild(child) had code that set
child.scene = ...

in complex applications since some Lifecycles had gameObject and others had scene

I tried to unify that in version 7 introducing some breaking changes and removing lifecycle.scene
that kind of broke a few things

so in this version v8 I have aimed to both:

1. unify gameObject and scene usage and types
2. fix bugs introduced in v7
3. improve code where possible (scene.pixi.isInitialized private -> public for example)