Fixed CodePushDemoAppTest compile error for iOS extension

Author: max-mironov

Examples/CodePushDemoApp/iOS/CodePushDemoAppTests/CodePushDemoAppTests.m

@@ -12,6 +12,7 @@
 
 #import <React/RCTLog.h>
 #import <React/RCTRootView.h>
+#import <React/RCTUtils.h>
 
 #define TIMEOUT_SECONDS 600
 #define TEXT_TO_LOOK_FOR @"Welcome to React Native!"
@@ -37,7 +38,7 @@ - (BOOL)findSubviewInView:(UIView *)view matching:(BOOL(^)(UIView *view))test
 
 - (void)testRendersWelcomeScreen
 {
-  UIViewController *vc = [[[[UIApplication sharedApplication] delegate] window] rootViewController];
+  UIViewController *vc = [[[RCTSharedApplication() delegate] window] rootViewController];
   NSDate *date = [NSDate dateWithTimeIntervalSinceNow:TIMEOUT_SECONDS];
   BOOL foundElement = NO;