explicitly require "onelogin/ruby-saml/logging"  so that the developer may do:
require 'onelogin/ruby-saml/authrequest'

instead of
require 'onelogin/ruby-saml'

or
require 'onelogin/ruby-saml/authrequest'
require 'onelogin/ruby-saml/logging'
Merge pull request #134 from nkeyes/master

explicitly require "onelogin/ruby-saml/logging"