Bugfix: Failure due to cugraph api change in v0.16...
Bugfix: Failure due to cugraph api change in v0.16...

Method cugraph.add_adj_list is replaced in RAPIDS v0.16 with from_cudf_adjlist.
This patch will check for existence of 'add_adj_list' in the object before
calling it.

theislab/scanpy,theislab/scanpy