Merge branch '4.4'

* 4.4:
  Fixing bug where PropertyInfoLoader tried to add validation to non-existent properties
  [TwigBundle] fix tests
  [travis] increase concurrency
  [FrameworkBundle] fix FC with HttpKernel v5

Tests/Compiler/ValidateEnvPlaceholdersPassTest.php

@@ -399,7 +399,7 @@ class ConfigurationWithArrayNodeRequiringOneElement implements ConfigurationInte
     public function getConfigTreeBuilder()
     {
         $treeBuilder = new TreeBuilder('env_extension');
-        $treeBuilder
+        $treeBuilder->getRootNode()
             ->children()
                 ->arrayNode('nodes')
                     ->isRequired()