Import .rda from URL into R

Question

I would like to set up code to download and load an .rda directly into R. The following code does not work, but illustrates what I am trying to do:

githubURL <- "https://github.com/ropensci/historydata/blob/master/data/catholic_dioceses.rda"
load(url(githubURL))
download.file(githubURL,"D")
load("D")

Thanks for any thoughts on how to adjust this code.