Transitions between stacked bar charts and splitting them up into smaller stacked bar charts.
forked from zachmargolis's block: Stack-to-Split Transition
forked from mashehu's block: Stack-to-split-Stack Transition with D3 v4
Modified http://d3js.org/d3.v4.min.js to a secure url
https://d3js.org/d3.v4.min.js