point_size argument to blandr.draw doesn't work with ggplot2

[vacmar01]

The point_size argument to blandr.draw() is not passed down to blandr.plot.ggplot() and therefore you can't change the point size when using ggplot2 as the plotting engine. Since blandr.plot.ggplot() uses geom_point() internally it should be an easy fix. It just needs to passed down from blandr.draw() to blandr.plot.ggplot() and then be used in geom_point().

I can try to provide a fix for it if it is wanted.

Edit: Did try a fix #21