Verify that we can now use unicode in GR-based labels, etc. with Plots

[jlperla]

The latest versions of GR might support using unicode labels. If so, we can slowly make transitions towards those.

But first lets verify that it is true in the whole pipeline.

Maybe on https://julia.quantecon.org/getting_started_julia/julia_by_example.html#A-Slightly-More-Useful-Function and see if something like the following works:

using Distributions

function plothistogram(distribution, n)
    ϵ = rand(distribution, n)  # n draws from distribution
    histogram(ϵ, label = "ϵ")
end

lp = Laplace()
plothistogram(lp, 500)

By works I mean that (1) the HTML that is generated by jupinx displays the label correct, (2) the generated jupyter notebooks do as well; and (3) no ugly warnings show up.

[jlperla]

Verified