GitLab

* update tree lstm

* tree_lstm (new interface)

* simplify pop

* merge qipeng(root)

* upd tree-lstm & tutorial

* upd model

* new capsule tutorial

* capsule for new API

* fix deprecated API

* New tutorial and example

* investigate gc problem

* add viz code

* new capsule tutorial

* remove ipynb

* move u_hat

* add link

* add requirements.txt

* remove ani.save

* update ci to install requirements

* utf-8

* change seed

* graphviz requirement

* accelerate

* little format

* update some markup