update workflow yml remove if for reqs install

.github/workflows/build_and_test.yml

@@ -24,7 +24,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install flake8 pytest coverage
-        if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+        pip install -r requirements.txt
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names