Add newsletters support to admin-api package

no issue

API clients like Zapier need to see newsletter resources

Author: sam-lord

packages/admin-api/lib/admin-api.js

@@ -143,7 +143,8 @@ module.exports = function GhostAdminAPI(options) {
         'tags',
         'webhooks',
         'members',
-        'users'
+        'users',
+        'newsletters'
     ];
 
     if (typeof config.version === 'string' && config.version.startsWith('v2')) {