title: GitHub repository autoloading with Composer issue
body: <p>I got <code>PHP Fatal error:  Class 'sendwithus\sendwithus_php\lib\API' not found</code></p>
  
  <p><strong>composer.json:</strong></p>
  
  <pre><code>{
      "repositories": {
          "sendwithus_php": {
              "type": "package",
              "package": {
                  "name": "sendwithus/sendwithus_php",
                  "version": "1.0.3",
                  "source": {
                      "url": "https://github.com/sendwithus/sendwithus_php",
                      "type": "git",
                      "reference": "0dfed56"
                  }
              }
          }
      },
      "require": {
          "sendwithus/sendwithus_php": "&gt;=1.0.3"
      }, "autoload": {
          "psr-0": {
              "Foo\\": "src/",
              "sendwithus\\": "vendor/sendwithus/sendwithus_php/lib"  
          }
      }, "minimum-stability" : "dev"
  }
  </code></pre>
  
  <p><strong>test.php:</strong></p>
  
  <pre><code>use sendwithus\sendwithus_php\lib\API;
  
  require_once 'vendor/autoload.php';
  
  $api = new API('KEY');
  </code></pre>
  
  <p>What am I doing wrong?</p>