Fix some lowest deps

Author: nicolas-grekas

composer.json

@@ -18,7 +18,7 @@
     "require": {
         "php": ">=5.3.9",
         "symfony/event-dispatcher": "~2.6,>=2.6.7|~3.0.0",
-        "symfony/http-foundation": "~2.8.8|~3.0.8",
+        "symfony/http-foundation": "~2.7.15|~2.8.8|~3.0.8",
         "symfony/debug": "~2.6,>=2.6.2",
         "psr/log": "~1.0"
     },