Update Configuration.php

Author: dquerioux

DependencyInjection/Configuration.php

@@ -169,7 +169,7 @@
  * - newrelic:
  *   - [level]: level name or int value, defaults to DEBUG
  *   - [bubble]: bool, defaults to true
- *   - [app_name]: new relic app name, default null
+ *   - [app-name]: new relic app name, default null
  *
  * - hipchat:
  *   - token: hipchat api token
@@ -293,7 +293,7 @@ public function getConfigTreeBuilder()
                             ->scalarNode('priority')->defaultValue(0)->end()
                             ->scalarNode('level')->defaultValue('DEBUG')->end()
                             ->booleanNode('bubble')->defaultTrue()->end()
-                            ->scalarNode('app_name')->defaultValue(null)->end()
+                            ->scalarNode('app-name')->defaultNull()->end()
                             ->booleanNode('include_stacktraces')->defaultFalse()->end()
                             ->scalarNode('path')->defaultValue('%kernel.logs_dir%/%kernel.environment%.log')->end() // stream and rotating
                             ->scalarNode('file_permission')  // stream and rotating