rely on Composer's autoloader and PHPUnit instead of the custom autoloader

Author: Christoph

lib/phpSec/Common/SplClassLoader.php

@@ -9,7 +9,7 @@
          processIsolation="false"
          stopOnFailure="false"
          syntaxCheck="false"
-         bootstrap="lib/phpSec/bootstrap.php"
+         bootstrap="vendor/autoload.php"
 >
     <testsuites>
         <testsuite name="phpSec Test Suite">
@@ -22,4 +22,4 @@
             <directory>./lib/</directory>
         </whitelist>
     </filter>
-</phpunit>
+</phpunit>