Symfony 4.2 compatibility. (#56)

* Symfony 4.2 compatibility.

* minor

* use phpunit 6.5

Author: Nyholm

.travis.yml

@@ -9,7 +9,7 @@ cache:
 env:
     global:
         - TEST_COMMAND="composer test"
-        - SYMFONY_PHPUNIT_VERSION="6.3"
+        - SYMFONY_PHPUNIT_VERSION="6.5"
 
 branches:
     except:
@@ -39,7 +39,7 @@ matrix:
           env: DEPENDENCIES="dunglas/symfony-lock:^4"
 
           # Latest commit to master
-        - php: 7.2
+        - php: 7.3
           env: STABILITY="dev"
 
     allow_failures:

DependencyInjection/Configuration.php

@@ -39,8 +39,13 @@ public function __construct($debug)
      */
     public function getConfigTreeBuilder()
     {
-        $treeBuilder = new TreeBuilder();
-        $root = $treeBuilder->root('neo4j');
+        $treeBuilder = new TreeBuilder('neo4j');
+        // Keep compatibility with symfony/config < 4.2
+        if (!method_exists($treeBuilder, 'getRootNode')) {
+            $root = $treeBuilder->root('neo4j');
+        } else {
+            $root = $treeBuilder->getRootNode();
+        }
 
         $root->children()
             ->arrayNode('profiling')