Add support for Symfony3.0

Author: kerihenare

composer.json

@@ -1,7 +1,7 @@
 {
     "name": "aws/aws-sdk-php-symfony",
     "description": "A Symfony bundle for v3 of the AWS SDK for PHP",
-    "keywords": [ "aws", "amazon", "symfony", "symfony2", "sdk"],
+    "keywords": [ "aws", "amazon", "symfony", "symfony2", "symfony3", "sdk"],
     "minimum-stability": "stable",
     "license": "Apache-2.0",
     "authors": [
@@ -13,14 +13,14 @@
     "require": {
         "php": ">=5.5",
         "aws/aws-sdk-php": "^3.2.6",
-        "symfony/config": "~2.3",
-        "symfony/dependency-injection": "~2.3",
-        "symfony/http-kernel": "~2.3"
+        "symfony/config": "~2.3|~3.0",
+        "symfony/dependency-injection": "~2.3|~3.0",
+        "symfony/http-kernel": "~2.3|~3.0"
     },
     "require-dev": {
         "phpunit/phpunit": "~4.7",
-        "symfony/framework-bundle": "~2.3",
-        "symfony/yaml": "~2.3"
+        "symfony/framework-bundle": "~2.3|~3.0",
+        "symfony/yaml": "~2.3|~3.0"
     },
     "autoload": {
         "psr-4": {