title: Expo + React Native version mismatch error ( JavaScript version: 0.55.4, Native version: 0.57.1 )
body: <p>I found lots of threads about this problem, but non of them helped me out.
  So sorry for writing another thread for the same problem.</p>
  
  <p>I am new to react-native and frankly packange.json is really painful for me to match version of dependencies.</p>
  
  <p>My package.json file is as follows.
  And, error message is </p>
  
  <pre><code>console.error: "React Native version mismatch.
  
  JavaScript version: 0.55.4
  Native version: 0.57.1
  ....."
  </code></pre>
  
  <p>I tried delete cache and node_modules and reinstall those things using following command. </p>
  
  <pre><code>"watchman watch-del-all &amp;&amp; rm -rf $TMPDIR/react-* &amp;&amp; rm -rf $TMPDIR/haste-map-react-native-packager-* &amp;&amp; rm -rf node_modules/&amp;&amp; npm install"
  </code></pre>
  
  <p>What I found from googling, in most cases, it was version mismatch between expo and react-native. But I believe I am using matched version of react-native and expo from expo website <a href="https://blog.expo.io/expo-sdk-30-0-0-is-now-available-e64d8b1db2a7" rel="noreferrer">Here</a></p>
  
  <pre><code>{
    "name": "empty-project-template",
    "main": "node_modules/expo/AppEntry.js",
    "private": true,
    "scripts": {
      "start": "expo start",
      "android": "expo start --android",
      "ios": "expo start --ios",
      "eject": "expo eject"
    },
    "dependencies": {
      "babel-core": "^7.0.0-bridge.0",
      "expo": "^30.0.0",
      "native-base": "^2.8.1",
      "react": "16.3.1",
      "react-native": "https://github.com/expo/react-native/archive/sdk-30.0.0.tar.gz",
      "react-navigation": "^2.11.2"
    },
    "devDependencies": {
      "@babel/core": "^7.1.6",
      "regenerator-runtime": "^0.13.1"
    }
  }
  </code></pre>