title: Why `npm update -g` is not updating my global packages to the latest version?
body: <p>I'm following steps from <a href="https://docs.npmjs.com/getting-started/updating-global-packages" rel="noreferrer">updating global packages</a>, so I executed <code>npm outdated -g --depth=0</code> and  got:</p>
  
  <pre><code>Package     Current  Wanted  Latest  Location
  typescript    2.2.2   2.2.2   2.4.1
  </code></pre>
  
  <p>Then, I executed <code>npm update -g</code>, but I still got the same output from <code>npm outdated -g --depth=0</code>.</p>
  
  <p>Executing <code>npm list -g --depth=0</code> also confirms that the typescript package has not been updated to 2.4.1:</p>
  
  <pre><code>+-- bower@1.8.0
  +-- gulp@3.9.1
  +-- typescript@2.2.2
  `-- typings@2.1.1
  </code></pre>
  
  <p>What am I missing?</p>