api: add a programmatic way to get a palette

[eamonnmag]

Would be cool to add something like this for your tool.
https://pypi.python.org/pypi/brewer2mpl/1.4

[connorgr]

There's actually similar functionality in Colorgorical – its just buried a bit in the code. Palette generation is completely independent from the server architecture, so you can run the following to make a palette:

numColors = 3
weights = { "ciede2000": 1.0, ... }
colorgorical = Model()
colorgorical.make(numColors, weights=weights)

I'll take a look at adding a terminal-bound example that highlights this.

Unfortunately you can't get around model initialization, unlike what's in the ColorBrewer API, since ColorBrewer is predefined and Colorgorical makes palettes on the fly.

[connorgr]

Kamil Slowikowski just wrote a gist that does something similar for using HTTP requests within R https://gist.github.com/slowkow/22daea426607416bfcd573ce9cbd89ab