Add xp-framework/io-collections to depencies

It was an indirect dependency via xp-framework/unittest before

Author: thekid

composer.json

@@ -9,6 +9,7 @@
     "xp-framework/core": "^9.0 | ^8.0 | ^7.0 | ^6.5",
     "xp-framework/logging": "^8.0 | ^7.0 | ^6.5",
     "xp-framework/networking": "^9.0 | ^8.0 | ^7.0 | ^6.6",
+    "xp-framework/io-collections": "^8.0 | ^7.0 | ^6.5",
     "php" : ">=5.6.0"
   },
   "require-dev" : {