chore: Suppress noisy logging during specs

This change uses StringIO.new instead of /dev/null in case someone wants to run
the specs on a non-Unix system.

Author: md5

spec/spec_helper.rb

@@ -15,6 +15,10 @@
 require 'rexml/xpath'
 require 'base64'
 
+TEST_LOGGER = Logger.new(StringIO.new)
+OneLogin::RubySaml::Logging.logger = TEST_LOGGER
+OmniAuth.config.logger = TEST_LOGGER
+
 RSpec.configure do |config|
   config.include Rack::Test::Methods
 end