Resolve #3472241 "Optionally support codemirroreditor"

Closes #3472241

composer.json

@@ -9,5 +9,7 @@
     "issues": "http://drupal.org/project/issues/menu_link_attributes",
     "source": "http://cgit.drupalcode.org/menu_link_attributes"
   },
-  "require": { }
+  "require": {
+    "drupal/codemirror_editor": "^1.0 || ^2.0"
+  }
 }