code: def workflow_transition(self, issue, status_name):
          
          transitions = self.transitions(issue)
          for transition in transitions:
              if transition['to']['name'] == status_name:
                  transition_id = transition['id']
                  self.transition_issue(issue, transition_id)
                  print "Changed status of issue %s to %s" % (issue.key, status_name)
                  return True
  
          print "Unable to change status of issue %s to %s" % (issue.key, status_name)
docs: Change the status of a JIRA issue to a named status.  Will only be updated
          if this transition is available from the current status.