Adjusting a test to pass even whether or not instance credentials are…

… available.

tests/Aws/Tests/Common/Client/ClientBuilderTest.php

@@ -222,9 +222,17 @@ public function testAddsDefaultCredentials()
         // Ensure that specific credentials can be used
         $client1 = ClientBuilder::factory('Aws\\DynamoDb')->setConfig($config)->build();
         $this->assertSame($creds, $client1->getCredentials());
-        unset($config['credentials']);
 
         // Ensure that the instance metadata service is called when no credentials are supplied
+        $imc = $this->getMock(
+            'Aws\Common\InstanceMetadata\InstanceMetadataClient',
+            array('getInstanceProfileCredentials'),
+            array($this->getMock('Guzzle\Common\Collection'))
+        );
+        $imc->expects($this->any())->method('getInstanceProfileCredentials')
+            ->willThrowException(new \Aws\Common\Exception\InstanceProfileCredentialsException);
+        unset($config['credentials']);
+        $config['credentials.client'] = $imc;
         $client2 = ClientBuilder::factory('Aws\\DynamoDb')->setConfig($config)->build();
         try {
             $client2->getCredentials()->getAccessKeyId();