title: React Native / Xcode Upgrade and now RCTConvert.h not found
body: <p>App ran fine on React Native 0.35.0. After updating to 0.40.0 via <code>react-native-git-upgrade</code> I get a number of lexical/preprocessor issues when trying to build/run the app in XCode. </p>
  
  <p><code>React/RCTBridgeModule.h' file not found</code></p>
  
  <p>When clicking on the issue I see this highlighted:</p>
  
  <p><code>#import &lt;React/RCTBridgeModule.h&gt;</code></p>
  
  <p>It doesn't appear to be a search path issue.</p>
  
  <p>I've tried deleting node_modules and running <code>npm install</code> again, but that hasn't fixed anything.</p>