Bump coffeescript from 2.6.0 to 2.6.1 in /modules/admin-ui-frontend

Bumps [coffeescript](https://github.com/jashkenas/coffeescript) from 2.6.0 to 2.6.1.
- [Release notes](https://github.com/jashkenas/coffeescript/releases)
- [Commits](jashkenas/coffeescript@2.6.0...2.6.1)

---
updated-dependencies:
- dependency-name: coffeescript
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

modules/admin-ui-frontend/package.json

@@ -65,7 +65,7 @@
     "html-validate": "html-validate 'app/**/*.html'"
   },
   "dependencies": {
-    "coffeescript": "^2.6.0",
+    "coffeescript": "^2.6.1",
     "node-sass": "^6.0.1"
   }
 }