Add PHPUnit configuration and bootstrap files

Introduced `phpunit.xml` for setting up our PHPUnit test suite with essential settings. Also added `bootstrap.php` to require necessary dependencies and import the `ConfigLib` library. This allows for a standardized testing environment and smoother test execution.

bootstrap.php

@@ -0,0 +1,3 @@
+<?php
+    require 'ncc';
+    import('net.nosial.configlib');

phpunit.xml

@@ -0,0 +1,11 @@
+<phpunit bootstrap="bootstrap.php">
+    <testsuites>
+        <testsuite name="ConfigLib Test Suite">
+            <directory>tests</directory>
+        </testsuite>
+    </testsuites>
+    <php>
+        <ini name="error_reporting" value="-1"/>
+        <server name="KERNEL_DIR" value="app/"/>
+    </php>
+</phpunit>