Update to drupal 8.0.0-rc1. For more information, see https://www.drupal.org/node/2582663

vendor/behat/mink/tests/Selector/PartialNamedSelectorTest.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace Behat\Mink\Tests\Selector;
+
+use Behat\Mink\Selector\PartialNamedSelector;
+
+class PartialNamedSelectorTest extends NamedSelectorTest
+{
+    protected function getSelector()
+    {
+        return new PartialNamedSelector();
+    }
+
+    protected function allowPartialMatch()
+    {
+        return true;
+    }
+}