remove unused package

Author: soyuka

composer.json

@@ -125,7 +125,6 @@
     "require-dev": {
         "behat/behat": "^3.11",
         "behat/mink": "^1.9",
-        "doctrine/cache": "^1.11 || ^2.1",
         "doctrine/common": "^3.2.2",
         "doctrine/dbal": "^4.0",
         "doctrine/doctrine-bundle": "^2.11 || ^3.1",