Fix lowest deps for GH-4972

Author: mvorisek

composer.json

@@ -36,10 +36,10 @@
         "phpunit/php-file-iterator": "^2.0.4",
         "phpunit/php-text-template": "^1.2.1",
         "phpunit/php-timer": "^2.1.2",
-        "sebastian/comparator": "^3.0.2",
+        "sebastian/comparator": "^3.0.5",
         "sebastian/diff": "^3.0.2",
         "sebastian/environment": "^4.2.3",
-        "sebastian/exporter": "^3.1.2",
+        "sebastian/exporter": "^3.1.5",
         "sebastian/global-state": "^3.0.0",
         "sebastian/object-enumerator": "^3.0.3",
         "sebastian/resource-operations": "^2.0.1",