title: can't install react-dom/test-utils via npm
body: <p>I've added two libraries to my <code>package.json</code></p>
  
  <pre><code>  "devDependencies": {
      ...
      "react-dom/test-utils": "*",
      "react-test-renderer/shallow": "*"
    },
  </code></pre>
  
  <p>as suggested by <a href="https://reactjs.org/docs/test-utils.html" rel="noreferrer">react docs</a> to be compliant with version 16 of <code>react</code> ecosystem.</p>
  
  <p>After running <code>npm install --verbose</code> I got this:</p>
  
  <pre><code>18 verbose node v8.5.0
  19 verbose npm  v5.3.0
  20 error code EINVALIDPACKAGENAME
  21 error Invalid package name "react-dom/test-utils": name can only contain URL-friendly characters
  22 verbose exit [ 1, true ]
  </code></pre>
  
  <p>Also trying to install it as <code>devDependency</code> via <strong>cli</strong> gives this error:</p>
  
  <pre><code>npm ERR! Error while executing:
  npm ERR! /usr/bin/git ls-remote -h -t ssh://git@github.com/react-dom/test-utils.git
  npm ERR! 
  npm ERR! Permission denied (publickey).
  npm ERR! fatal: Could not read from remote repository.
  npm ERR! 
  npm ERR! Please make sure you have the correct access rights
  npm ERR! and the repository exists.
  npm ERR! 
  npm ERR! exited with error code: 128
  </code></pre>
  
  <p><strong>How can I solve this to have those packages available for referencing in the code?</strong></p>