use requirements file for tests

.github/workflows/tests.yml

@@ -15,11 +15,11 @@ jobs:
         with:
           python-version: "3.9"
           cache: 'pip' # caching pip dependencies
-          
+
       - name: Install dependencies
         run: |
           pip install -e .
-          pip install pytest
+          pip install -r requirements-tests.txt
 
       - name: Run tests
         run: |