addLegendNumeric horizontal -> bins not working

[mtennekes]

Probably related to #82

library(leaflet)
data(quakes)
numPal <- colorNumeric('viridis', quakes$depth)
leaflet() %>%
	addTiles() %>%
	addLegendNumeric(
		pal = numPal,
		values = quakes$depth,
                orientation = "horizontal", 
                width = 200,
                bins = 10,
		position = 'topright',
		title = 'addLegendNumeric',
		group = 'Numeric Data'
	) 

I get:

In "vertical" orientation I get the expected ticks, i.e. 50, 100, ... 650.

[tomroh]

This is intentional as of right now. Horizontally placing non-overlapping text by the ticks is difficult given font-face differences in sizes. I could possibly add this in the future but it is up to the end user to play around to get the desired result.