Removes support for zend-stdlib v2 releases

Author: michalbundyra

composer.json

@@ -20,7 +20,7 @@
     "require": {
         "php": "^5.6 || ^7.0",
         "zendframework/zend-loader": "^2.5.1",
-        "zendframework/zend-stdlib": "^3.1 || ^2.7.7",
+        "zendframework/zend-stdlib": "^3.2.1",
         "zendframework/zend-uri": "^2.5.2",
         "zendframework/zend-validator": "^2.10.1"
     },