[Bugfix] Fix sample adj (THUDM#301)

* Fix sample_adj & docs

[Docs] Update docs & examples (THUDM#292)

* Fix docs

* Update docs

[Doc] v0.4.1 (THUDM#270)

[Doc] v0.4 release (THUDM#236)

[Doc] v0.3.0 release (THUDM#200)

[Release] New v0.2.0 release (THUDM#163)

New 0.1.2 release (THUDM#57)

Merge pull request THUDM#36 from yaoxingcheng/master

Add GATLayer for gcc

Fix node classification loss