Merge pull request #223 from mujuonly/patch-1

Update PngRenderer.php

Author: casperbakker

src/Renderers/PngRenderer.php

@@ -27,7 +27,7 @@ public function __construct()
         } elseif (function_exists('imagecreate')) {
             $this->useImagick = false;
         } else {
-            throw new BarcodeException('Neither gd-lib or imagick are installed!');
+            throw new BarcodeException('Neither the GD library nor the Imagick extension is installed!');
         }
     }