added phpunit config for testing coverage

.gitignore

@@ -2,3 +2,6 @@
 vendor/
 composer.phar
 composer.lock
+.phpunit.result.cache
+coverage/
+.vscode/settings.json

phpunit.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd"
+	executionOrder="random"
+	beStrictAboutOutputDuringTests="true"
+	beStrictAboutTodoAnnotatedTests="true"
+	convertDeprecationsToExceptions="true"
+	stopOnError="true"
+	stopOnFailure="true"
+	verbose="true"
+	colors="true">
+  <coverage processUncoveredFiles="true">
+    <include>
+      <directory suffix=".php">flight/</directory>
+    </include>
+  </coverage>
+  <testsuites>
+    <testsuite name="default">
+      <directory>tests/</directory>
+    </testsuite>
+  </testsuites>
+  <logging/>
+</phpunit>

tests/FlightTest.php

@@ -18,9 +18,16 @@ class FlightTest extends PHPUnit\Framework\TestCase
 {
     protected function setUp(): void
     {
+		$_SERVER = [];
+		$_REQUEST = [];
         Flight::init();
     }
 
+	protected function tearDown(): void {
+		unset($_REQUEST);
+		unset($_SERVER);
+	}
+
     // Checks that default components are loaded
     public function testDefaultComponents()
     {

tests/RequestTest.php

@@ -17,6 +17,8 @@ class RequestTest extends PHPUnit\Framework\TestCase
 
     protected function setUp(): void
     {
+		$_SERVER = [];
+		$_REQUEST = [];
         $_SERVER['REQUEST_URI'] = '/';
         $_SERVER['SCRIPT_NAME'] = '/index.php';
         $_SERVER['REQUEST_METHOD'] = 'GET';
@@ -34,6 +36,11 @@ class RequestTest extends PHPUnit\Framework\TestCase
         $this->request = new Request();
     }
 
+	protected function tearDown(): void {
+		unset($_REQUEST);
+		unset($_SERVER);
+	}
+
     public function testDefaults()
     {
         self::assertEquals('/', $this->request->url);

tests/RouterTest.php

@@ -23,11 +23,18 @@ class RouterTest extends PHPUnit\Framework\TestCase
 
     protected function setUp(): void
     {
+		$_SERVER = [];
+		$_REQUEST = [];
         $this->router = new Router();
         $this->request = new Request();
         $this->dispatcher = new Dispatcher();
     }
 
+	protected function tearDown(): void {
+		unset($_REQUEST);
+		unset($_SERVER);
+	}
+
     // Simple output
     public function ok()
     {