adding pytest runner as well

.github/workflows/runtests.yml

@@ -1,4 +1,4 @@
-name: Pytest
+name: Run Tests with Pytest
 
 on: [push, pull_request]
 
@@ -18,6 +18,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
+          if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
           pip install pytest
 
       - name: Run pytest