[ticket/14250] Fix composer.json

Symfony dependencies that aren't required by phpBB itself but by
one of its dependencies are now forced to be 2.8 LTS again.

PHPBB3-14250

phpBB/composer.json

@@ -43,16 +43,21 @@
 		"symfony/routing": "2.8.*",
 		"symfony/twig-bridge": "2.8.*",
 		"symfony/yaml": "2.8.*",
-		"twig/twig": "1.*"
+		"twig/twig": "1.*",
+
+		"symfony/debug": "2.8.*"
 	},
 	"require-dev": {
-		"fabpot/goutte": "1.0.*@dev",
-		"phing/phing": "2.4.*@dev",
-		"phpunit/dbunit": "1.3.*@dev",
-		"phpunit/phpunit": "4.1.*@dev",
-		"sami/sami": "1.*@dev",
-		"squizlabs/php_codesniffer": "2.*@dev",
+		"fabpot/goutte": "1.0.*",
+		"phing/phing": "2.4.*",
+		"phpunit/dbunit": "1.3.*",
+		"phpunit/phpunit": "4.1.*",
+		"sami/sami": "1.*",
+		"squizlabs/php_codesniffer": "2.*",
 		"symfony/browser-kit": "2.8.*@dev",
-		"symfony/dom-crawler": "2.8.*@dev"
+		"symfony/dom-crawler": "2.8.*@dev",
+
+		"symfony/css-selector": "2.8.*@dev",
+		"symfony/process": "2.8.*@dev"
 	}
 }