require only specific symfony components instead of whole framework

Author: prgTW

composer.json

@@ -14,9 +14,12 @@
 		}
 	],
 	"require": {
-		"php": ">=5.3.3",
-		"symfony/symfony": "~2.3|~3.0",
-		"docplanner/gatekeeper": "2.*"
+		"php": ">=5.4",
+		"docplanner/gatekeeper": "2.*",
+		"symfony/dependency-injection": "^2.8|^3.0",
+		"symfony/http-kernel": "^2.8|^3.0",
+		"symfony/config": "^2.8|^3.0",
+		"symfony/security": "^2.8|^3.0"
 	},
 	"autoload": {
 		"psr-4": {