GitLab

* [Model][Core] GATv2

* lint

* gatv2conv.py

* lint

* lint

* style and docs

* lint

* gatv2conv fix
Co-authored-by: Shaked Brody shakedbr@campus.technion.ac.il <shakedbr@tangerine.cslcs.technion.ac.il>
Co-authored-by: Mufei Li <mufeili1996@gmail.com>