Summary:
A few people have been complaining, including me, that when we compile a react native project, there are a lot of warnings from xcode, suggesting to update the project build settings to the new recommendations.
I took the liberty to actually update the xcode projects, so we can finally have these gone, as well as replace some deprecated methods with the new suggested ones.
I made two react native projects, one with the regular react native and the other one using this branch.
Left is before, right is after:
![screen shot 2018-06-05 at 15 44 34](https://user-images.githubusercontent.com/100233/40979899-6aba12da-68d7-11e8-8630-6c3009b6dc24.png)
[IOS] [MINOR] [Xcode] - updated the Xcode projects with the latest suggestions from Xcode 9.3, and replaced a few deprecated methods of iOS with their new replacements.
Closes https://github.com/facebook/react-native/pull/19574
Differential Revision: D8489006
Pulled By: hramos
fbshipit-source-id: 2922b2e76aca6883c4f5d04e9c511b9fc1029583