* WIP

* Apply default options when screen options are null

* modal animations

* fix tests

* refactor

* refactor

* refactor

* refactor

* test fix

* topBar anim

* child disappear bug

* Update app.js

* Update WelcomeScreen.js

* fix tests

* bottom tabs

* stack id

* fix test

* refactoring

* merge fix

* Update app.js

* merge

* comment to fix test