fixed Composer constraints

Tests/DebugClassLoaderTest.php

@@ -11,10 +11,11 @@
 
 namespace Symfony\Component\Debug\Tests;
 
+use PHPUnit\Framework\TestCase;
 use Symfony\Component\Debug\DebugClassLoader;
 use Symfony\Component\Debug\ErrorHandler;
 
-class DebugClassLoaderTest extends \PHPUnit_Framework_TestCase
+class DebugClassLoaderTest extends TestCase
 {
     /**
      * @var int Error reporting level before running tests

Tests/ErrorHandlerTest.php

@@ -11,6 +11,7 @@
 
 namespace Symfony\Component\Debug\Tests;
 
+use PHPUnit\Framework\TestCase;
 use Psr\Log\LogLevel;
 use Symfony\Component\Debug\ErrorHandler;
 use Symfony\Component\Debug\Exception\ContextErrorException;
@@ -21,7 +22,7 @@ use Symfony\Component\Debug\Exception\ContextErrorException;
  * @author Robert Schönthal <seroscho@googlemail.com>
  * @author Nicolas Grekas <p@tchwork.com>
  */
-class ErrorHandlerTest extends \PHPUnit_Framework_TestCase
+class ErrorHandlerTest extends TestCase
 {
     public function testRegister()
     {

Tests/Exception/FlattenExceptionTest.php

@@ -11,6 +11,7 @@
 
 namespace Symfony\Component\Debug\Tests\Exception;
 
+use PHPUnit\Framework\TestCase;
 use Symfony\Component\Debug\Exception\FlattenException;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 use Symfony\Component\HttpKernel\Exception\MethodNotAllowedHttpException;
@@ -27,7 +28,7 @@ use Symfony\Component\HttpKernel\Exception\ServiceUnavailableHttpException;
 use Symfony\Component\HttpKernel\Exception\TooManyRequestsHttpException;
 use Symfony\Component\HttpKernel\Exception\UnsupportedMediaTypeHttpException;
 
-class FlattenExceptionTest extends \PHPUnit_Framework_TestCase
+class FlattenExceptionTest extends TestCase
 {
     public function testStatusCode()
     {

Tests/ExceptionHandlerTest.php

@@ -11,6 +11,7 @@
 
 namespace Symfony\Component\Debug\Tests;
 
+use PHPUnit\Framework\TestCase;
 use Symfony\Component\Debug\ExceptionHandler;
 use Symfony\Component\Debug\Exception\OutOfMemoryException;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
@@ -18,7 +19,7 @@ use Symfony\Component\HttpKernel\Exception\MethodNotAllowedHttpException;
 
 require_once __DIR__.'/HeaderMock.php';
 
-class ExceptionHandlerTest extends \PHPUnit_Framework_TestCase
+class ExceptionHandlerTest extends TestCase
 {
     protected function setUp()
     {

Tests/FatalErrorHandler/ClassNotFoundFatalErrorHandlerTest.php

@@ -11,6 +11,7 @@
 
 namespace Symfony\Component\Debug\Tests\FatalErrorHandler;
 
+use PHPUnit\Framework\TestCase;
 use Symfony\Component\ClassLoader\ClassLoader as SymfonyClassLoader;
 use Symfony\Component\ClassLoader\UniversalClassLoader as SymfonyUniversalClassLoader;
 use Symfony\Component\Debug\Exception\FatalErrorException;
@@ -18,7 +19,7 @@ use Symfony\Component\Debug\FatalErrorHandler\ClassNotFoundFatalErrorHandler;
 use Symfony\Component\Debug\DebugClassLoader;
 use Composer\Autoload\ClassLoader as ComposerClassLoader;
 
-class ClassNotFoundFatalErrorHandlerTest extends \PHPUnit_Framework_TestCase
+class ClassNotFoundFatalErrorHandlerTest extends TestCase
 {
     public static function setUpBeforeClass()
     {

Tests/FatalErrorHandler/UndefinedFunctionFatalErrorHandlerTest.php

@@ -11,10 +11,11 @@
 
 namespace Symfony\Component\Debug\Tests\FatalErrorHandler;
 
+use PHPUnit\Framework\TestCase;
 use Symfony\Component\Debug\Exception\FatalErrorException;
 use Symfony\Component\Debug\FatalErrorHandler\UndefinedFunctionFatalErrorHandler;
 
-class UndefinedFunctionFatalErrorHandlerTest extends \PHPUnit_Framework_TestCase
+class UndefinedFunctionFatalErrorHandlerTest extends TestCase
 {
     /**
      * @dataProvider provideUndefinedFunctionData

Tests/FatalErrorHandler/UndefinedMethodFatalErrorHandlerTest.php

@@ -11,10 +11,11 @@
 
 namespace Symfony\Component\Debug\Tests\FatalErrorHandler;
 
+use PHPUnit\Framework\TestCase;
 use Symfony\Component\Debug\Exception\FatalErrorException;
 use Symfony\Component\Debug\FatalErrorHandler\UndefinedMethodFatalErrorHandler;
 
-class UndefinedMethodFatalErrorHandlerTest extends \PHPUnit_Framework_TestCase
+class UndefinedMethodFatalErrorHandlerTest extends TestCase
 {
     /**
      * @dataProvider provideUndefinedMethodData

composer.json

@@ -24,7 +24,7 @@
     },
     "require-dev": {
         "symfony/class-loader": "~2.2",
-        "symfony/http-kernel": "~2.3.24|~2.5.9|~2.6,>=2.6.2"
+        "symfony/http-kernel": "~2.3.24|~2.5.9|^2.6.2"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\Debug\\": "" },