Updating to latest integration tests

Author: Nyholm

composer.json

@@ -32,7 +32,7 @@
     },
     "require-dev":       {
         "phpunit/phpunit":         "^4.0 || ^5.1",
-        "cache/integration-tests": "^0.12"
+        "cache/integration-tests": "^0.13"
     },
     "provide":           {
         "psr/cache-implementation": "^1.0"