Remove NavigatorIOS

Summary:
Legacy navigator impl. There are other alternatives that should be used instead.

Part of the slimmening effort as described here: https://github.com/react-native-community/discussions-and-proposals/issues/6

Reviewed By: TheSavior

Differential Revision: D9677824

fbshipit-source-id: 24ae500751d2a8c398f246d36604a58f0b3c113b

Libraries/react-native/react-native-implementation.js

@@ -66,9 +66,6 @@ const ReactNative = {
   get Modal() {
     return require('Modal');
   },
-  get NavigatorIOS() {
-    return require('NavigatorIOS');
-  },
   get Picker() {
     return require('Picker');
   },
@@ -325,6 +322,13 @@ const ReactNative = {
         'Learn about alternative navigation solutions at http://facebook.github.io/react-native/docs/navigation.html',
     );
   },
+  get NavigatorIOS() {
+    invariant(
+      false,
+      'NavigatorIOS is deprecated and has been removed from this package. ' +
+        'Learn about alternative navigation solutions at http://facebook.github.io/react-native/docs/navigation.html',
+    );
+  },
 };
 
 module.exports = ReactNative;