2.4

• Added: filter_subscribers method for https://developers.kit.com/api-reference/subscribers/filter-subscribers-based-on-engagement: #118
• Added: update_subscriber_custom_field_values method for https://developers.kit.com/api-reference/custom-fields/bulk-update-subscriber-custom-field-values: #119
• Added: custom_field.* event types to create_webhook method for https://developers.kit.com/api-reference/webhooks/create-a-webhook: #120