Pretty printing of distributions with UnicodePlots.barplot

[Zachary Sunberg]

This could be really useful for visually explaining how transition and observation are supposed to return a distribution. It would look like this:

https://github.com/Evizero/UnicodePlots.jl#barplot

[Zachary Sunberg]

(we could get rid of the 0.0 entry)

[Mykel Kochenderfer]

So pretty!!!