Adding Finance app to showcase

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Closes https://github.com/facebook/react-native/pull/6688

Differential Revision: D3184356

fb-gh-sync-id: d508150202373ccb6c33f6af16ef545222463f98
fbshipit-source-id: d508150202373ccb6c33f6af16ef545222463f98

website/src/react-native/showcase.js

@@ -355,6 +355,12 @@ var apps = [
     link: 'https://play.google.com/store/apps/details?id=com.arjunkomath.product_hunt&hl=en',
     author: 'Arjun Komath',
   },
+  {
+    name: 'Finance',
+    icon: 'https://lh3.googleusercontent.com/3VIk0kX6WyaHdQkNJVdFqW6Kn-O-rZ1RUwvu1tjQamRC33ThMIGh3dkRALpSRPjUIw=w300-rw',
+    link: 'https://play.google.com/store/apps/details?id=com.kfpun.finance&hl=en',
+    author: 'kf (@7kfpun)',
+  },
   {
     name: 'Fixt',
     icon: 'http://a5.mzstatic.com/us/r30/Purple69/v4/46/bc/66/46bc66a2-7775-4d24-235d-e1fe28d55d7f/icon175x175.png',