[FEATURE] Added Request::getContentType for content-type header-parsing

- Added unit-tests for Request::getContentType parsing.

tests/Pecee/SimpleRouter/RequestTest.php

@@ -0,0 +1,38 @@
+<?php
+
+use Pecee\Http\Input\InputFile;
+
+require_once 'Dummy/DummyMiddleware.php';
+require_once 'Dummy/DummyController.php';
+require_once 'Dummy/Handler/ExceptionHandler.php';
+
+class RequestTest extends \PHPUnit\Framework\TestCase
+{
+
+    public function testContentTypeParse()
+    {
+        global $_SERVER;
+
+        $contentType = 'application/x-www-form-urlencoded';
+        $_SERVER['content_type'] = $contentType;
+
+        $router = TestRouter::router();
+        $router->reset();
+
+        $request = $router->getRequest();
+
+        $this->assertEquals($contentType, $request->getContentType());
+
+        // Test special content-types
+        $router->reset();
+
+        $_SERVER['content_type'] = 'application/x-www-form-urlencoded; charset=UTF-8';
+
+        $this->assertEquals($contentType, $request->getContentType());
+
+        $router->reset();
+    }
+
+    // TODO: implement more test-cases
+
+}