Update iOS headers for React Native 0.40

- Also add explicit React-Native version (0.40) dependency to package.json

Author: abrahambotros

ios/RCTSplashScreen/RCTSplashScreen/RCTSplashScreen.h

@@ -1,5 +1,5 @@
-#import "RCTBridgeModule.h"
-#import "RCTRootView.h"
+#import <React/RCTBridgeModule.h>
+#import <React/RCTRootView.h>
 
 @interface RCTSplashScreen : NSObject <RCTBridgeModule>
 

package.json

@@ -23,5 +23,8 @@
   "bugs": {
     "url": "https://github.com/react-native-component/react-native-smart-splash-screen/issues"
   },
-  "homepage": "https://github.com/react-native-component/react-native-smart-splash-screen#readme"
+  "homepage": "https://github.com/react-native-component/react-native-smart-splash-screen#readme",
+  "dependencies": {
+    "react-native": "^0.40.0"
+  }
 }