Reinstate missing Github actions linting step

Author: echarrod

.github/workflows/tests.yaml

@@ -48,4 +48,8 @@ jobs:
 
       - run: pushd examples/aml && pip install -r requirements.txt && popd
 
+      - run: pushd examples/yoti_example_django && pip install -r requirements.txt && popd
+
       - run: pushd examples/yoti_example_flask && pip install -r requirements.txt && popd
+
+      - run: pushd examples/doc_scan && pip install -r requirements.txt && popd