GitLab

* add multihead in DotGatConv

* Fix spacing issue

* Add Unit test for dotgat

* Modified Unit test for dotgat

* Add transformer like divisor

* Update dotgatconv.py

* Update hgao.py

* Update train.py
Co-authored-by: Chen <chesirui@3c22fbe5458c.ant.amazon.com>
Co-authored-by: Zihao Ye <expye@outlook.com>