test universal flag

package.json

@@ -55,7 +55,8 @@
       "category": "public.app-category.graphics-design",
       "entitlements": "build/entitlements.mac.plist",
       "entitlementsInherit": "build/entitlements.mac.plist",
-      "notarize": false
+      "notarize": false,
+      "arch": ["universal"]
     },
     "icon": "build/icon.icns",
     "appId": "openbuilds.control",