title: Composer error with GitHub OAuth token on fresh laravel/homestead provision
body: <p>Fresh installed a <code>laravel/homestead</code> vagrant box, as per docs, run the <code>init.sh</code>, configured <code>Homestead.yaml</code> and ran <code>$ vagrant up; vagrant ssh</code>. Afterwards <code>cd</code>'ed to project's folder and ran <code>composer install</code>.</p>
  
  <p>It hangs waiting for a <code>token</code> with the following message</p>
  
  <pre><code>Loading composer repositories with package information
  Installing dependencies (including require-dev) from lock file
  - Installing sebastian/diff (1.3.0)
  Downloading: Connecting...
  Could not fetch https://api.github.com/repos/sebastianbergmann/diff/zipball/863df9687835c62aa423a22412d26fa2ebde3fd3, please create a GitHub OAuth token to go over the API rate limit
  Head to https://github.com/settings/tokens/new?scopes=repo&amp;description=Composer+on+homestead+2015-08-01+2140
  to retrieve a token. It will be stored in "/home/vagrant/.composer/auth.json" for future use by Composer.
  Token (hidden):
  </code></pre>
  
  <p>I have used <code>laravel/homestead</code> before, and I have never had to do any of these, is this some <em>undocumented</em> new feature or a bug or did I do something wrong?</p>