Added some CAS and SAML settings. Not tested. Please test and send pull requests if it does not work.

See https://github.com/wekan/wekan/wiki/SAML and https://github.com/wekan/wekan/wiki/CAS

Thanks to xet7 !

Related #3204,
related #708

client/components/main/layouts.js

@@ -169,6 +169,19 @@ async function authentication(event, templateInstance) {
         });
       });
 
+    case 'saml':
+      return new Promise(resolve => {
+        const provider = Meteor.settings.public.SAML_PROVIDER;
+        Meteor.loginWithSaml(
+          {
+            provider,
+          },
+          function() {
+            resolve(FlowRouter.go('/'));
+          },
+        );
+      });
+
     case 'cas':
       return new Promise(resolve => {
         Meteor.loginWithCas(match, password, function() {