Install R from MRAN date into electricShine folder
install_r(cran_like_url = NULL, app_root_path,
mac_url = "https://mac.r-project.org/el-capitan/R-3.6-branch/R-3.6-branch-el-capitan-sa-x86_64.tar.gz",
permission_to_install = FALSE)
CRAN-like url e.g. https://cran.r-project.org/bin/windows/base
path to current electricShine app build
mac R installer url
have permission to install R?