title: Unmet Peer Dependency react-native@0.40.0
body: <p>I'm using <code>npm install react-native@0.40.0 --save</code> to upgrade React Native, but I keep getting an error that I have an "UNMET PEER DEPENDENCY react-native@0.40.0".
  <br><br>
  This confuses me because I thought I had just installed react-native@0.40.0.</p>