chore(release): publish

- netlify-cms-app@2.9.4
 - netlify-cms-backend-git-gateway@2.4.4
 - netlify-cms-core@2.12.0
 - netlify-cms-lib-auth@2.2.3
 - netlify-cms-widget-relation@2.4.0
 - netlify-cms@2.9.4

packages/netlify-cms-widget-relation/package.json

@@ -1,7 +1,7 @@
 {
   "name": "netlify-cms-widget-relation",
   "description": "Widget for linking related entries in Netlify CMS.",
-  "version": "2.3.3",
+  "version": "2.4.0",
   "homepage": "https://www.netlifycms.org/docs/widgets/#relation",
   "repository": "https://github.com/netlify/netlify-cms/tree/master/packages/netlify-cms-widget-relation",
   "bugs": "https://github.com/netlify/netlify-cms/issues",