Add Revolut fiat payment provider

- Add revolut partner entry to src/demo/partners.ts
- Type: fiat
- Color: #191C33 (Revolut dark navy/purple brand color)
- Positioned alphabetically between paytrie and safello

Author: Bobby The Lobster

src/demo/partners.ts

@@ -105,6 +105,10 @@ export default {
     type: 'fiat',
     color: '#99A5DE'
   },
+  revolut: {
+    type: 'fiat',
+    color: '#191C33'
+  },
   safello: {
     type: 'fiat',
     color: deprecated