Change demo link

Author: kulgavy

README.md

@@ -2,7 +2,7 @@
 
 Responsive admin dashboard template built with Vue.js and Bootstrap 4. Developed with ❤️ by [Flatlogic](https://flatlogic.com/).
 
-[View Demo](http://sing-app-vue.herokuapp.com) | [Download](https://github.com/flatlogic/sing-app-vue-dashboard/archive/master.zip) | [More templates](https://flatlogic.com/admin-dashboards)
+[View Demo](https://demo.flatlogic.com/sing-app-vue-dashboard/) | [Download](https://github.com/flatlogic/sing-app-vue-dashboard/archive/master.zip) | [More templates](https://flatlogic.com/admin-dashboards)
 
 ![image](https://user-images.githubusercontent.com/24964748/48494482-05a3ba80-e83f-11e8-95e6-4a6d2e76687b.png)