GitLab

* add more unit tests for mxnet.

* fix.

* change ci

* update ci

* update ci

* update ci

* update ci

* update ci

* update ci

* update ci

* update ci

* update ci

* update ci

* update ci

* update ci

* update ci

* update ci

* update ci

* nx package

* update ci

* update ci

* update ci

* fix

* mx dockerfile by zhengda

* python3.6->3.5

* update ci image

* add tutorial test

* fix ci

* fix ssl problem

* minor change

* small fix on traversal utest

* fix syntax

* add matplotlib in image

* fix

* update ci

* update ci

* bfs with edges

* dfs toy test case

* clean up

* style fix

* bugfix

* updating docs for bfs_edges and readouts

* Fix bug in bfs and topo

* remove legacy codes

* bfs, dfs and topological traversal

* dfs and test cases

* Conflicts:
	python/dgl/graph.py
	src/graph/graph.cc
	src/graph/graph_op.cc

* documentation

* requested changes

* Conflicts:
	Jenkinsfile
	examples/pytorch/gcn/gcn.py
	examples/pytorch/gcn/gcn_spmv.py
	python/dgl/graph.py
	python/dgl/graph_index.py
	src/graph/graph.cc
	src/graph/graph_op.cc

* Conflicts:
	Jenkinsfile
	python/dgl/graph_index.py

* fix lint errors

* fix lint errors

* fix lint errors

* fix test cases

* requested changes

* traversal interface

* [Bug] fixed a typo that caused syntax error (#120)

* WIP

* bfs nodes generator works

* topological traversal

* WIP: dfs_edges

* dfs edges

* dfs labeled edges

* utest for traversal

* fix lint

* fix utest

* code clean

* changes as requested