Update php-saml to 3.2.1

composer.json

@@ -107,7 +107,7 @@
         "libraries/progress-tracker": "v1.4.0",
         "libraries/signature-pad": "v2.3.0",
         "mikey179/vfsstream": "~1.2",
-        "onelogin/php-saml": "~3.0.0",
+        "onelogin/php-saml": "~3.2.1",
         "oomphinc/composer-installers-extender": "v1.1.2",
         "phpunit/phpunit": ">=4.8.28 <5",
         "symfony/browser-kit": ">=2.8.13 <3.0",