v2.0.0

• Switch to d3v5, this only means changing the way d3.json and d3.csv work (using Promises).
• Rewritten the snippets using ES2015.
• New snippet for using Promise.all to load files. This is the way to do it now as d3-queue is no longer recommended.
• New snippet for d3.max.
• New snippet for d3.min.