chore(release): publish

- netlify-cms-app@2.10.0-beta.4
 - netlify-cms-core@2.13.0-beta.9
 - netlify-cms-locales@1.3.0-beta.1
 - netlify-cms-ui-default@2.7.0-beta.4
 - netlify-cms@2.10.0-beta.4

packages/netlify-cms-core/package.json

@@ -1,7 +1,7 @@
 {
   "name": "netlify-cms-core",
   "description": "Netlify CMS core application, see netlify-cms package for the main distribution.",
-  "version": "2.13.0-beta.8",
+  "version": "2.13.0-beta.9",
   "repository": "https://github.com/netlify/netlify-cms/tree/master/packages/netlify-cms-core",
   "bugs": "https://github.com/netlify/netlify-cms/issues",
   "module": "dist/esm/index.js",