title: Composer Require: Could not find package
body: <p>I'm trying to use this: <a href="https://github.com/digitaldonkey/ethereum-php" rel="noreferrer">https://github.com/digitaldonkey/ethereum-php</a></p>
  
  <p>so I run: <code>composer require digitaldonkey/ethereum-php</code> but I get:</p>
  
  <blockquote>
    <p>[InvalidArgumentException]<br>
    Could not find package digitaldonkey/ethereum-php at any version for
    your minimum-stability (stable). Check the package spelling or your
    minimum-stability</p>
  </blockquote>
  
  <p>So I imagine I need to specify some other branch but what?</p>