Add basic test for password drivers

plugins/password/tests/Password.php

@@ -20,6 +20,20 @@ class Password_Plugin extends PHPUnit_Framework_TestCase
         $this->assertInstanceOf('rcube_plugin', $plugin);
     }
 
+    /**
+     * A dummy test testing PHP syntax on password drivers
+     */
+    function test_all_drivers()
+    {
+        if ($files = glob(__DIR__ . '/../drivers/*.php')) {
+            foreach ($files as $file) {
+                if (preg_match('|/([a-z_]+)\.php$|', $file, $matches)) {
+                    $this->load_driver($matches[1]);
+                }
+            }
+        }
+    }
+
     /**
      * cpanel_webmail driver test
      */