Update composer.json to support Symfony 3.x

Author: arnogeurts

composer.json

@@ -12,7 +12,7 @@
     ],
     "require": {
         "php": ">=5.3.3",
-        "symfony/options-resolver": "2.x"
+        "symfony/options-resolver": "^2.3||^3.0"
     },
     "autoload": {
         "psr-0" : { "Jatun" : "lib/" }