Merge branch '2.7' into 2.8

* 2.7:
  Create PULL_REQUEST_TEMPLATE.md
  Remove duplicate validation in RedirectResponse
  [Yaml] fix default timezone to be UTC
  [DependencyInjection] fix dumped YAML string
  [Config] Add suggest to composer.json for symfony/yaml

Conflicts:
	src/Symfony/Component/DependencyInjection/Dumper/YamlDumper.php

Author: nicolas-grekas

Dumper/YamlDumper.php

@@ -89,7 +89,7 @@ private function addService($id, $definition)
         }
 
         if ($definition->getFile()) {
-            $code .= sprintf("        file: %s\n", $definition->getFile());
+            $code .= sprintf("        file: %s\n", $this->dumper->dump($definition->getFile()));
         }
 
         if ($definition->isSynthetic()) {
@@ -125,11 +125,11 @@ private function addService($id, $definition)
         }
 
         if ($definition->getFactoryMethod(false)) {
-            $code .= sprintf("        factory_method: %s\n", $definition->getFactoryMethod(false));
+            $code .= sprintf("        factory_method: %s\n", $this->dumper->dump($definition->getFactoryMethod(false)));
         }
 
         if ($definition->getFactoryService(false)) {
-            $code .= sprintf("        factory_service: %s\n", $definition->getFactoryService(false));
+            $code .= sprintf("        factory_service: %s\n", $this->dumper->dump($definition->getFactoryService(false)));
         }
 
         if ($definition->getArguments()) {
@@ -149,7 +149,7 @@ private function addService($id, $definition)
         }
 
         if (ContainerInterface::SCOPE_CONTAINER !== $scope = $definition->getScope(false)) {
-            $code .= sprintf("        scope: %s\n", $scope);
+            $code .= sprintf("        scope: %s\n", $this->dumper->dump($scope));
         }
 
         if (null !== $decorated = $definition->getDecoratedService()) {