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

vendor/phpspec/prophecy/spec/Prophecy/Exception/Doubler/InterfaceNotFoundExceptionSpec.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace spec\Prophecy\Exception\Doubler;
+
+use PhpSpec\ObjectBehavior;
+use spec\Prophecy\Exception\Prophecy;
+
+class InterfaceNotFoundExceptionSpec extends ObjectBehavior
+{
+    function let()
+    {
+        $this->beConstructedWith('msg', 'CustomInterface');
+    }
+
+    function it_extends_ClassNotFoundException()
+    {
+        $this->shouldBeAnInstanceOf('Prophecy\Exception\Doubler\ClassNotFoundException');
+    }
+
+    function its_getClassname_returns_classname()
+    {
+        $this->getClassname()->shouldReturn('CustomInterface');
+    }
+}