ci: speedup dependencies installations by using binaries

Using the Posit Public Package Manager

Refs #175

.gitignore

@@ -58,6 +58,7 @@ vignettes/*.pdf
 
 # R Environment Variables
 .Renviron
+.Rprofile
 
 # pkgdown site
 docs/

.gitlab-ci.yml

@@ -17,6 +17,7 @@ cache:
 before_script:
   - mkdir -p $R_LIBS_USER
   - echo "R_LIBS='$R_LIBS_USER'" > .Renviron
+  - echo 'options(repos = c(CRAN = "https://packagemanager.posit.co/cran/__linux__/focal/latest"))' > .Rprofile
   - apt-get update && apt-get install -y libstdc++6
   - R -q -e 'remotes::install_deps(dependencies = TRUE)'
 
@@ -42,13 +43,6 @@ before_script:
   image: rocker/geospatial:4.1
   variables:
     R_VERSION: oldrel
-  before_script:
-    - mkdir -p $R_LIBS_USER
-    - echo "R_LIBS='$R_LIBS_USER'" > .Renviron
-    - apt-get update && apt-get install -y tk libstdc++6
-    - R -q -e 'remotes::update_packages("sm")'
-    - R -q -e 'install.packages("vioplot")'
-    - R -q -e 'remotes::install_deps(dependencies = TRUE)'
 
 .scheduled_tests:
   only: