v2.1.0

• Allow d3.randomBates to take fractional n.
• Allow d3.randomIrwinHall to take fractional n.
• Add d3.randomGamma.
• Add d3.randomBeta.
• Add d3.randomWeibull.
• Add d3.randomCauchy.
• Add d3.randomLogistic.
• Add d3.randomPoisson.

Thanks to @Parcly-Taxel for the contributions!