Updated react-native example to 0.48.4

Author: cesardeazevedo

example/package.json

@@ -9,7 +9,7 @@
   },
   "dependencies": {
     "react": "16.0.0-alpha.12",
-    "react-native": "0.47.1",
+    "react-native": "0.48.4",
     "react-native-collapsing-toolbar": "file:../",
     "react-native-vector-icons": "^4.3.0"
   },