Collect organisation type

So that we can default services to their appropriate text allowance, we
need to find out what sector they're in. So let's start collecting that
from teams as they create new services.

I think Central/Local/NHS are the right options, but these can be easily
changed if not.

tests/app/notify_client/test_service_api_client.py

@@ -43,3 +43,38 @@ def test_client_only_updates_allowed_attributes(mocker):
     with pytest.raises(TypeError) as error:
         ServiceAPIClient().update_service('service_id', foo='bar')
     assert str(error.value) == 'Not allowed to update service attributes: foo'
+
+
+def test_client_creates_service_with_correct_data(
+    mocker,
+    active_user_with_permissions,
+    fake_uuid,
+):
+    client = ServiceAPIClient()
+    mock_post = mocker.patch.object(client, 'post')
+    mocker.patch('app.notify_client.current_user', id='123')
+
+    client.create_service(
+        service_name='My first service',
+        organisation_type='central_government',
+        message_limit=1,
+        restricted=True,
+        user_id=fake_uuid,
+        email_from='test@example.com',
+    )
+    mock_post.assert_called_once_with(
+        '/service',
+        dict(
+            # Autogenerated arguments
+            created_by='123',
+            active=True,
+            # ‘service_name’ argument is coerced to ‘name’
+            name='My first service',
+            # The rest pass through with the same names
+            organisation_type='central_government',
+            message_limit=1,
+            restricted=True,
+            user_id=fake_uuid,
+            email_from='test@example.com',
+        ),
+    )