title: Unable to resolve module by using native-base
body: <p>I take a reference from <a href="https://docs.nativebase.io/" rel="nofollow noreferrer">https://docs.nativebase.io/</a> , when i try to use the sample code it shows the error <code>Unable to resolve module</code> , it just like the photo
  <a href="https://i.stack.imgur.com/RCOCF.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/RCOCF.png" alt="enter image description here"></a>
  My environment is:</p>
  
  <pre><code>"expo": "^18.0.4",
  "native-base": "^2.2.1",
  "react": "16.0.0-alpha.12",
  "react-native": "https://github.com/expo/react-native/archive/sdk-18.0.1.tar.gz",
  </code></pre>
  
  <p>Here is my App.js:</p>
  
  <pre><code>import React from 'react';
  // import { StyleSheet, View, Text } from 'react-native';
  import { Container, Button, Text } from 'native-base';
  
  export default class App extends React.Component {
  
    render() {
      return (
        &lt;Container&gt;
          &lt;Button&gt;
            &lt;Text&gt;
              Button
            &lt;/Text&gt;
          &lt;/Button&gt;
        &lt;/Container&gt;
      );
    }
  }
  
  const styles = StyleSheet.create({
    container: {
      flex: 1,
      backgroundColor: '#fff',
      alignItems: 'center',
      justifyContent: 'center',
    },
  });
  </code></pre>
  
  <p>I find that i just import 'native-base' cause the error <code>import { Container, Button, Text } from 'native-base';</code></p>
  
  <p>Please tell me what step i miss it . Thanks in advance.</p>