[FEATURE] Added ExceptionHandling functionality + tests.

- Somehow the ExceptionHandling functionality never really get implemented and/or got lost in translation, it's back whup!
- Added some basic tests for Middleware + routing.

test/Dummy/DummyController.php

@@ -0,0 +1,9 @@
+<?php
+
+class DummyController {
+
+    public function start() {
+        echo static::class . '@' .'start() OK';
+    }
+
+}

test/Dummy/DummyMiddleware.php

@@ -0,0 +1,14 @@
+<?php
+
+require_once 'Exceptions/MiddlewareLoadedException.php';
+
+use Pecee\Http\Middleware\IMiddleware;
+use Pecee\Http\Request;
+
+class DummyMiddleware implements IMiddleware {
+
+    public function handle(Request $request) {
+       throw new MiddlewareLoadedException('Middleware loaded!');
+    }
+
+}

test/Dummy/Exceptions/MiddlewareLoadedException.php

@@ -0,0 +1,2 @@
+<?php
+class MiddlewareLoadedException extends \Exception {}