updated readme

README.md

@@ -27,7 +27,7 @@ For example, this package replaces the native [NavigatorIOS](https://facebook.gi
 
 ## Installation - iOS
 
- * Make sure you are using react-native version >= 0.19.0
+ * Make sure you are using react-native version >= 0.25.1
 
  * In your project folder run `npm install react-native-navigation --save`
 > Note: We recommend using npm ver 3+. If you insist on using npm ver 2 please notice that the location for react-native-controllers in node_modules will be under the react-native-navigation folder and you'll need to change the paths in Xcode below accordingly.