GitLab

* multigraph support on graph index

* more tests

* multigraph flag, bugfix on clear & copy

* networkx interfaces

* including graph index tests in Jenkins

* node subgraph test

* edge subgraphs

* removing duplicates in pred/succ

* more explicit test and doc

* query source and destination from edge id

* subgraphindex

* renaming has_edge to has_edge_between, apply_edges adding eid

* send_on and send_and_recv_on

* DGLGraph edge subgraph

* merged send_on and send_and_recv_on

* change request

* removing hashmap

* creating multigraph by flag; mingw support

* changes per request

* reverting networkx auto multigraph discovery

* notes on send/send_and_recv on multigraphs

* changing test reducer from sum to max

* added a fixme note in spmv scheduler