Updated CI/CD to check for requirements.txt

.github/workflows/pylint.yml

@@ -18,7 +18,7 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           pip install pylint
-          pip install -r requirements.txt
+          if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
       - name: Analysing the code with pylint
         run: |
           pylint $(git ls-files '*.py')