Fix HandlerLoaderTest::testHandlerForProcessor

ProcessableHandlerInterface::pushProcessor expects the $callback argument to be a callable. Fix the following error:

PHPUnit 5.7.27 by Sebastian Bergmann and contributors.

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Time: 101 ms, Memory: 8.00MB

There was 1 error:

1) Cascade\Tests\Config\Loader\ClassLoader\HandlerLoaderTest::testHandlerForProcessor
TypeError: Argument 1 passed to Mock_TestHandler_f2eedf4c::pushProcessor() must be callable, string given, called in /home/danilo/monolog-cascade/src/Config/Loader/ClassLoader/HandlerLoader.php on line 187

/home/danilo/monolog-cascade/src/Config/Loader/ClassLoader/HandlerLoader.php:187
/home/danilo/monolog-cascade/tests/Config/Loader/ClassLoader/HandlerLoaderTest.php:263

tests/Config/Loader/ClassLoader/HandlerLoaderTest.php

@@ -244,8 +244,15 @@ public function testHandlerForProcessor()
     {
         $options = array();
 
-        $mockProcessor1 = '123';
-        $mockProcessor2 = '456';
+        $mockProcessor1 = function($record) {
+            $record['extra']['dummy'] = 'Hello world 1!';
+            return $record;
+        };
+        $mockProcessor2 =  function($record) {
+            $record['extra']['dummy'] = 'Hello world 2!';
+            return $record;
+        };
+
         $processorsArray = array($mockProcessor1, $mockProcessor2);
 
         // Setup mock and expectations