Remove integration testing content

This is covered in the new client library documentation. All of the
client libraries now have their documentation published in the new
format.

tests/app/main/views/test_index.py

@@ -55,7 +55,7 @@ def test_robots(client):
 
 
 @pytest.mark.parametrize('view', [
-    'cookies', 'privacy', 'using_notify', 'pricing', 'terms', 'integration_testing', 'roadmap',
+    'cookies', 'privacy', 'using_notify', 'pricing', 'terms', 'roadmap',
     'features', 'callbacks', 'documentation', 'security'
 ])
 def test_static_pages(
@@ -106,6 +106,23 @@ def test_old_static_pages_redirect(
     )
 
 
+def test_old_integration_testing_page(
+    client_request,
+):
+    page = client_request.get(
+        'main.integration_testing',
+        _expected_status=410,
+    )
+    assert normalize_spaces(page.select_one('.grid-row').text) == (
+        'Integration testing '
+        'This information has moved. '
+        'Refer to the documentation for the client library you are using.'
+    )
+    assert page.select_one('.grid-row a')['href'] == url_for(
+        'main.documentation'
+    )
+
+
 def test_terms_is_generic_if_user_is_not_logged_in(
     client
 ):