Merge pull request #195 from RomanKosovnenko/fix/logout_request_signature_validation

fix: Signature validation on IdP initiated SLO

Author: bufferoverflow

lib/omniauth/strategies/saml.rb

@@ -177,7 +177,7 @@ def handle_logout_response(raw_response, settings)
       end
 
       def handle_logout_request(raw_request, settings)
-        logout_request = OneLogin::RubySaml::SloLogoutrequest.new(raw_request)
+        logout_request = OneLogin::RubySaml::SloLogoutrequest.new(raw_request, {}.merge(settings: settings).merge(get_params: @request.params))
 
         if logout_request.is_valid? &&
           logout_request.name_id == session["saml_uid"]