Match VCR request body as xml doc rather than string. Will account for different versions of LibXML outputting slightly different XML (mainly empty tags) even though the xml document is equivalent. Uses http://rubygems.org/gems/equivalent-xml

vcr.rb

VCR.configure do |c|
  c.register_request_matcher :xml_body do |request_1, request_2|
    EquivalentXml.equivalent?(request_1.body, request_2.body)
  end
  c.ignore_localhost = true
  c.cassette_library_dir = Rails.root.join("spec", "support", "vcr_cassettes")
  c.hook_into :webmock
  c.configure_rspec_metadata!
  c.default_cassette_options = { match_requests_on: [:method, :uri, :xml_body] }
  # c.debug_logger = File.open("#{Rails.root}/log/vcr.log", 'w')
end

Article about custom matcher in VCR http://myronmars.to/n/dev-blog/2011/10/custom-request-matchers-in-vcr-2-0