Allow psr/cache v3 but on symfony/cache

Author: nicolas-grekas

composer.json

@@ -17,7 +17,7 @@
     ],
     "require": {
         "php": ">=7.1.3",
-        "psr/cache": "^1.0|^2.0"
+        "psr/cache": "^1.0|^2.0|^3.0"
     },
     "suggest": {
         "symfony/cache-implementation": ""