tests: add UI load test

tests/test_ui.py

+import pytest
+import requests
+
+
+@pytest.mark.unit
+def test_default_search_field(endpoint, api_key):
+
+    # Check the UI does not generate 50X Errors
+    resp = requests.post('{endpoint}/account/settings/applications/'.format(
+        endpoint=endpoint))
+
+    assert resp.status_code == 200