Making cache tags more efficient by rewriting the API.

Related to php-cache/issues#21

Author: Nyholm

composer.json

@@ -31,7 +31,7 @@
     "require-dev":       {
         "phpunit/phpunit":         "^4.0|^5.1",
         "cache/array-adapter":     "@stable",
-        "cache/integration-tests": "0.7.0"
+        "cache/integration-tests": "0.9.0"
     },
     "autoload":          {
         "psr-4":                 {