composer: remove version

packagist figures out version automatically from git tag, no need to
update it manually

Author: glensc

composer.json

@@ -2,7 +2,6 @@
     "name": "onelogin/php-saml",
     "description": "OneLogin PHP SAML Toolkit",
     "license": "MIT",
-    "version": "2.11.0",
     "homepage": "https://onelogin.zendesk.com/hc/en-us/sections/200245634-SAML-Toolkits",
     "keywords": ["saml", "saml2", "onelogin"],
     "autoload": {