[TASK] Add new Acceptance Tests folder to splitter script

To speed up execution of acceptance tests in bamboo, the available
test files are split into work packages. The script only considers
test files located in typo3/sysext/core/Acceptance/Backend.

With the new main folder InstallTool, that contains tests concerning
the stand alone install tool, the script must also consider those
files for work packages.

Author: Anja Leichsenring

Resources/Core/Build/Scripts/splitAcceptanceTests.php

@@ -80,7 +80,7 @@ public function execute()
         // Find functional test files
         $testFiles = (new Finder())
             ->files()
-            ->in(__DIR__ . '/../../../../../../../typo3/sysext/core/Tests/Acceptance/Backend')
+            ->in([__DIR__ . '/../../../../../../../typo3/sysext/core/Tests/Acceptance/Backend', __DIR__ . '/../../../../../../../typo3/sysext/core/Tests/Acceptance/InstallTool'])
             ->name('/Cest\.php$/')
         ;