update path

.github/workflows/build.yml

@@ -21,7 +21,7 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           pip install flake8
-          pip install -r requirements.txt
+          pip install -r ./app/requirements.txt
       - name: Lint with flake8
         run: |
           # stop the build if there are Python syntax errors or undefined names