hsv method
Creates chalk with foreground color defined from HSV (Hue, Saturation and Value) color space parameters. https://en.wikipedia.org/wiki/HSL_and_HSV
Implementation
Chalk hsv(num hue, num saturation, num value) {
var rgb = ColorUtils.hsv2rgb(hue, saturation, value);
return makeRGBChalk(rgb[0], rgb[1], rgb[2]);
}