Add SoundCloud Pulse to the app showcase

Summary:Simple PR that adds SoundCloud Pulse to the app showcase
Closes https://github.com/facebook/react-native/pull/6224

Differential Revision: D2994345

fb-gh-sync-id: 97c81c9149f90bf10c4b04ff79eeaf9f8710f26c
shipit-source-id: 97c81c9149f90bf10c4b04ff79eeaf9f8710f26c

website/src/react-native/showcase.js

@@ -110,6 +110,12 @@ var featured = [
       'https://blog.gyrosco.pe/the-making-of-gyroscope-running-a4ad10acc0d0',
     ],
   },
+  {
+    name: 'SoundCloud Pulse',
+    icon: 'https://i1.sndcdn.com/artworks-000149203716-k5je96-original.jpg',
+    link: 'https://itunes.apple.com/us/app/soundcloud-pulse-for-creators/id1074278256?mt=8',
+    author: 'SoundCloud',
+  },
   {
     name: 'Spero for Cancer',
     icon: 'https://s3-us-west-1.amazonaws.com/cancerspot/site_images/Spero1024.png',