Remove direction constraint from geom_chicklet()

[charliejhadley]

This is absolutely a nice to have feature, I'm not entirely clear how to implement it myself but may come back in the future to this.

In {ggplot2} 3.3.0 geoms were extended to work in either direction, meaning coord_flip() is no longer required. The {ggplot2} implementation can be found here https://github.com/tidyverse/ggplot2/pull/3506

[brunomioto]

+1