title: error when run "composer install"
body: <p>i got this error when tried to run "composer install" for a laravel 5 project:</p>
  
  <pre><code>You are running composer with xdebug enabled. This has a major impact on runtime performance. See https://getcomposer.org/xdebug
  Loading composer repositories with package information
  Installing dependencies (including require-dev) from lock file
  Your requirements could not be resolved to an installable set of packages.
  
    Problem 1
      - Installation request for intervention/image 2.3.4 -&gt; satisfiable by intervention/image[2.3.4].
      - intervention/image 2.3.4 requires ext-fileinfo * -&gt; the requested PHP extension fileinfo is missing from your system.
  </code></pre>
  
  <p>I've tried set the PHP.ini xdebug to false, and still got this error. What should i do to solve this error? how to disable the xdebug? or is there anything else that should i did? thanks.</p>