Install R dependencies

Fix issue with fairadapt dependency igraph: https://r.igraph.org/articles/installation-troubleshooting.html#cannot-compile-igraph-from-sources-on-linux

Signed-off-by: Samuel Hoffman <hoffman.sc@gmail.com>

.github/workflows/ci.yml

@@ -43,6 +43,7 @@ jobs:
 
       - name: Install dependencies
         run: |
+          sudo apt install libglpk-dev libxml2-dev
           python -m pip install --upgrade pip setuptools wheel
           pip install -e '.[all]'
           pip install flake8