Changing from devtools to remotes based installation.

The remotes package was split from the larger devtools package and is
now the recommended package to use for installation from git
repositories. This updates the documentation and the GitHub workflow.

Author: zivy

.github/workflows/main.yml

@@ -46,10 +46,10 @@ jobs:
         R --version
     - name: Install R packages
       run: |
-        R -e "install.packages(c('git2r', 'devtools'), lib=c('${R_LIBS}'), repo='https://cloud.r-project.org/')"
+        R -e "install.packages(c('git2r', 'remotes'), lib=c('${R_LIBS}'), repo='https://cloud.r-project.org/')"
     - name: Build and test
       run: |
         set -x
-        R -e "devtools::install(c('.'), lib=c('${R_LIBS}'), args=c('--configure-vars="MAKEJ=2"'))"
+        R -e "remotes::install_git(c('.'), lib=c('${R_LIBS}'), configure.vars=c('"MAKEJ=2"'))"
       env:
         ITK_GLOBAL_DEFAULT_NUMBER_OF_THREADS: 2

README.md

@@ -4,15 +4,15 @@
 ![Build Status](https://github.com/SimpleITK/SimpleITKRInstaller/actions/workflows/main.yml/badge.svg)
 
 
-A devtools based installer for SimpleITK R installer.
+A [remotes](https://github.com/r-lib/remotes) based installer for SimpleITK in [R](https://www.r-project.org/).
 
 ```R
-devtools::install_github("SimpleITK/SimpleITKRInstaller")
+remotes::install_github("SimpleITK/SimpleITKRInstaller")
 ```
 or, turn on mutlicore compilation using
 
 ```R
-devtools::install_github("SimpleITK/SimpleITKRInstaller", args=c("--configure-vars=MAKEJ=6"))
+remotes::install_github("SimpleITK/SimpleITKRInstaller", configure.vars=c("MAKEJ=6"))
 ```
 
 Requires _cmake_ and _git_ in the path.