Add missing requirement-tests installation

.github/workflows/pygeppetto-tests.yml

@@ -23,7 +23,7 @@ jobs:
           python -m pip install --upgrade pip
           pip install pytest
           pip install -r requirements.txt
-          pip install -r requirements.txt
+          pip install -r requirements-test.txt
           pip install -e .
       - name: Test with pytest
         run: |