title: issues when autoloading files with psr-4
body: <p>I've been trying to get psr-4 autoloading work for over a week now with no success. </p>
  
  <p>My file structure is as follows:</p>
  
  <pre><code>-Project
    -src
      -classes
         session.php
    -vendor
    index.php
  </code></pre>
  
  <p>I've created the psr-4 autoload function as follows:</p>
  
  <pre><code> "autoload": {
          "psr-4": {
           "classes\\": "src/classes"
      }
  
  }
  </code></pre>
  
  <p>after using composer dump-autoload -0 ,inside my session.php class I gave the namespace:</p>
  
  <pre><code>namespace classes;
  
  class session{
  
  public static function exist($name){
  
      return(isset($_SESSION[$name])) ? true : false;
  }
  </code></pre>
  
  <p>I then required the autoloader and used the use function to name the session class as follows:</p>
  
  <pre><code>use src\classes\session as session;
  
  require_once('vendor/autoload.php');
  
  session::put('test', 'test');
  </code></pre>
  
  <p>after opening up the index.php page, I get a </p>
  
  <blockquote>
    <p>Fatal error: Class 'src\classes\session' not found in /var/www/test/Project/index.php on line 10</p>
  </blockquote>
  
  <p>is my directory structure / php correct? I've tried many different guides online and can't seem to get it to work.</p>