Update documentation to use cudf version 0.18.1#1934

Merged

revans2 merged 4 commits intoNVIDIA:branch-0.4from sameerz:branch-0.4-cudf-0.18.1

Mar 15, 2021

+13-13

Commits on Mar 13, 2021

Update cudf version to 0.18.1 in the docs
sameerz
committed

Commits on Mar 15, 2021