title: Composer is not recognizing PHP 7
body: <p>I created a travis profile to test my project from PHP 5.6 to PHP 7.</p>
  
  <p>I am getting the following error when composer is run:</p>
  
  <pre><code>Your requirements could not be resolved to an installable set of packages.
    Problem 1
      - This package requires php ~5.4 but your PHP version (7.0.1-dev) does not satisfy that requirement.
  </code></pre>
  
  <p>the command that I am running is:</p>
  
  <pre><code>composer update -n
  </code></pre>
  
  <p>with travis set to environment PHP 5.6 I do not run into this issue</p>