title: github tags and composer
body: <p>I wonder why if I tag a package on github with f.e. <code>v1.0.0</code>, when I require it with composer it says:</p>
  
  <blockquote>
    <p>Importing tag v1.0.0 (1.0.0.0)</p>
  </blockquote>
  
  <p>always adding one 0 to the tag given.</p>
  
  <p>How does composer version matching works?</p>