Ebauche de montée de version vers symfony3

composer.json

@@ -22,13 +22,13 @@
     ],
     "require": {
         "php": ">=5.4",
-        "symfony/symfony": "~2.6",
+        "symfony/symfony": "~2.8|~3.0",
         "doctrine/orm": "~2.2,>=2.2.3",
         "doctrine/doctrine-bundle": "~1.2",
         "symfony/assetic-bundle": "~2.3",
-        "symfony/monolog-bundle": "~2.4",
+        "symfony/monolog-bundle": "~2.4|~3.0",
         "sensio/framework-extra-bundle": "~3.0",
-        "irstea/theme-bundle": "~1.5",
+        "irstea/theme-bundle": "^1.5|^2.0",
         "knplabs/knp-gaufrette-bundle": "~0.1",
         "ramsey/uuid": "~2.8",
         "blueimp/jquery-file-upload": "~9.9",
@@ -53,7 +53,8 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "0.1-dev"
+            "dev-master": "0.1-dev",
+            "dev-symfony3": "1.0.x-dev"
         }
     },
     "archive": {