Updating imagine bundle for cache control

Author: Dylan Schoenmakers

composer.json

@@ -20,7 +20,7 @@
         "gedmo/doctrine-extensions": "~2.3",
         "jms/serializer-bundle": "~0.13",
         "knplabs/knp-gaufrette-bundle": "*@dev",
-        "liip/imagine-bundle": "~1.0.2",
+        "liip/imagine-bundle": "~1.2.6",
         "pagerfanta/pagerfanta": "~1.0"
     },
     "require-dev": {