title: npm Error: Cannot find module 'core-util-is'
body: <p>When I run</p>
  
  <pre><code>npm -v, npm install and npm install --save react-native-voice
  </code></pre>
  
  <p>this error appears: </p>
  
  <pre><code>module.js:549
      throw err;
      ^
  
  Error: Cannot find module 'core-util-is'
  
      at Function.Module._resolveFilename (module.js:547:15)
      at Function.Module._load (module.js:474:25)
      at Module.require (module.js:596:17)
      at require (internal/module.js:11:18)
      at Object.&lt;anonymous&gt; (/usr/local/lib/node_modules/npm/node_modules/readable-stream/lib/_stream_readable.js:67:12)
      at Module._compile (module.js:652:30)
      at Object.Module._extensions..js (module.js:663:10)
      at Module.load (module.js:565:32)
      at tryModuleLoad (module.js:505:12)
      at Function.Module._load (module.js:497:3)
  </code></pre>