Allow psr/cache ^1.0 || ^2.0 (#255)

All packages now allow v1 and v2.

Author: ruudk

composer.json

@@ -26,7 +26,7 @@
         "php": "^5.6 || ^7.0 || ^8.0",
         "cache/adapter-common": "^1.0",
         "cache/hierarchical-cache": "^1.0",
-        "psr/cache": "^1.0",
+        "psr/cache": "^1.0 || ^2.0",
         "psr/simple-cache": "^1.0"
     },
     "require-dev": {