MAGETWO-34305: Support pull requests until merged

Author: sivaschenko

dev/tests/functional/composer.json

@@ -1,6 +1,6 @@
 {
     "require": {
-        "magento/mtf": "1.0.0-rc18",
+        "magento/mtf": "1.0.0-rc19",
         "php": "~5.5.0|~5.6.0",
         "phpunit/phpunit": "4.1.0",
         "phpunit/phpunit-selenium": ">=1.2",