Update class Workflow to use convert_xml()
Update class Workflow to use convert_xml()

Change-Id: I54f45afd3b5218ad6ed7103400458ebfc8135067

puppetlabs/jenkins-job-builder,rsig/jenkins-job-builder,gforcada/jenkins-job-builder,gforcada/jenkins-job-builder,gforcada/jenkins-job-builder,rsig/jenkins-job-builder,wikimedia/integration-jenkins-job-builder,phinexus/jenkins-job-builder,wsoula/jenkins-job-builder,phinexus/jenkins-job-builder,OSSystems/jenkins-job-builder,wikimedia/integration-jenkins-job-builder,puppetlabs/jenkins-job-builder,phinexus/jenkins-job-builder,gforcada/jenkins-job-builder,phinexus/jenkins-job-builder,rsig/jenkins-job-builder,gforcada/jenkins-job-builder,puppetlabs/jenkins-job-builder,puppetlabs/jenkins-job-builder,wikimedia/integration-jenkins-job-builder,wikimedia/integration-jenkins-job-builder,OSSystems/jenkins-job-builder,rsig/jenkins-job-builder,OSSystems/jenkins-job-builder,phinexus/jenkins-job-builder,wsoula/jenkins-job-builder,OSSystems/jenkins-job-builder,wikimedia/integration-jenkins-job-builder,wsoula/jenkins-job-builder,wsoula/jenkins-job-builder