Update continuous-integration-workflow.yml (#20)

Author: tobiasraabe

.github/workflows/continuous-integration-workflow.yml

@@ -23,9 +23,6 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
-      - uses: r-lib/actions/setup-r@v1
-        with:
-          r-version: ${{ matrix.r-version }}
       - uses: conda-incubator/setup-miniconda@v2
         with:
           auto-update-conda: true