add javascript ajax example

examples/javascript/tests/conftest.py

@@ -0,0 +1,15 @@
+import pytest
+
+from js_example import app
+
+
+@pytest.fixture(name='app')
+def fixture_app():
+    app.testing = True
+    yield app
+    app.testing = False
+
+
+@pytest.fixture
+def client(app):
+    return app.test_client()