Merge pull request SAML-Toolkits#465 from puzzledmonkey/patch-1

Update composer.json to add ext-zlib as a dependency

Author: pitbulk

composer.json

@@ -21,7 +21,8 @@
         "ext-curl": "*",
         "ext-openssl": "*",
         "ext-dom": "*",
-        "ext-mcrypt": "*"
+        "ext-mcrypt": "*",
+        "ext-zlib": "*"
     },
     "require-dev": {
         "phpunit/phpunit": "4.8",