Update default colours when no scale_colour is specified

[aaronw22]

Currently lines, bars, points are black when no scale_colour is specified.

We can change this default by adding update_geom_defaults() to .onLoad in zzz.R.

Add this code:

# Update default colour
geoms_colour <- c("point", "line", "pointrange", "errorbar", "boxplot")
lapply(geoms_colour, update_geom_defaults, new = aes(colour = e61_tealdark))

# Update default fill
geoms_fill <- c("col")
lapply(geoms_fill, update_geom_defaults, new = aes(fill= e61_tealdark))

# Update defaults for other types
update_geom_defaults("ribbon", aes(fill= e61_tealdark, alpha = 0.1))