need to skip this test on HHVM, Aspect Mock doesn't work there.

tests/src/Provider/Node/SystemNodeProviderTest.php

@@ -19,8 +19,8 @@ class SystemNodeProviderTest extends TestCase
 
         $this->assertTrue(ctype_xdigit($node), 'Node is not a hexadecimal string. Actual node: ' . $node);
         $this->assertTrue(strlen($node) === 12, 'Node is 12 characters long. Actual length: ' . strlen(
-            $node
-        ) . PHP_EOL . ' Actual node: ' . $node);
+                $node
+            ) . PHP_EOL . ' Actual node: ' . $node);
     }
 
 
@@ -90,6 +90,7 @@ class SystemNodeProviderTest extends TestCase
      */
     public function testGetNodeGetsNetworkInterfaceConfig($os, $command)
     {
+        $this->skipIfHhvm();
         AspectMock::func('Ramsey\Uuid\Provider\Node', 'php_uname', $os);
         $passthru = AspectMock::func('Ramsey\Uuid\Provider\Node', 'passthru', 'whatever');