Update composer to fit Symfony 3

Author: mattmortek

composer.json

@@ -10,15 +10,15 @@
     "minimum-stability": "stable",
     "require": {
         "php": ">=5.3.0",
-        "symfony/twig-bundle": "~2.1",
-        "symfony/framework-bundle": "~2.1",
-        "symfony/finder" : "~2.1"
+        "symfony/twig-bundle": "~2.1|3.*",
+        "symfony/framework-bundle": "~2.1|3.*",
+        "symfony/finder" : "~2.1|3.*"
     },
     "require-dev" : {
-        "symfony/css-selector": "~2.1",
-        "symfony/browser-kit": "~2.1",
-        "symfony/yaml": "~2.1",
-        "sensio/framework-extra-bundle": "~2.1"
+        "symfony/css-selector": "~2.1|3.*",
+        "symfony/browser-kit": "~2.1|3.*",
+        "symfony/yaml": "~2.1|3.*",
+        "sensio/framework-extra-bundle": "~2.1|3.*"
     },
     "license": "MIT",
     "autoload": {