Update README.md

ReactAndroid/README.md

@@ -14,7 +14,7 @@ Make sure you have the following installed:
 
 - Android SDK version 23 (compileSdkVersion in [`build.gradle`](build.gradle))
 - SDK build tools version 23.0.1 (buildToolsVersion in [`build.gradle`](build.gradle))
-- Android Support Repository 20 (for Android Support Library)
+- Android Support Repository >= 17 (for Android Support Library)
 - Android NDK (download & extraction instructions [here](http://developer.android.com/ndk/downloads/index.html))
  
 Point Gradle to your Android SDK: either have `$ANDROID_SDK` and `$ANDROID_NDK` defined, or create a `local.properties` file in the root of your `react-native` checkout with the following contents: