If you want to have access to all the packages in this repository (rtlemos), here are the steps:
# install the real drat package from CRAN
install.packages('drat')
# add my repo to your list of repos (for your current R session only), thanks to my drat package
drat::addRepo(account = 'rtlemos', alturl = 'https://rtlemos.github.io/drat/')
# installing a package (and its dependencies) from my repo, e.g. rcvirtual
install.packages('rcvirtual')My local version of drat is just a dummy package that lets you do the above seamlessly.
You don't need to download it or use it explicitly.
To learn more about the real drat package, by Dirk Eddelbuettel, read the vignette and FAQ.