Revert "Merge pull request #52 from pykih/d3.chart.river"

This reverts commit 13784e2c70e20261f0a17d52847dbcb963c3ea0a, reversing
changes made to 02151f553edc3d2184e603c14e022ae4c8dd07f8.
Merge pull request #56 from prometheansacrifice/revertPR52

Revert "Merge pull request #52 from pykih/d3.chart.river"