Added adapters as dev dependencies

Author: Nyholm

composer.json

@@ -24,7 +24,10 @@
     },
     "require-dev":  {
         "phpunit/phpunit":                                  "5.0.*|^4.0",
-        "matthiasnoback/symfony-dependency-injection-test": "0.7.*"
+        "matthiasnoback/symfony-dependency-injection-test": "0.7.*",
+        "cache/doctrine-adapter": "@stable",
+        "cache/redis-adapter": "@stable",
+        "cache/memcached-adapter": "@stable"
     },
     "autoload":     {
         "psr-4": {