'Render a Tropo object into a Json string.'

def RenderJson(self, pretty=False):

    steps = self._steps
    topdict = {}
    topdict['tropo'] = steps
    logging.info(('topdict:    %s' % topdict))
    if pretty:
        try:
            json = jsonlib.dumps(topdict, indent=4, sort_keys=False)
        except TypeError:
            json = jsonlib.dumps(topdict)
    else:
        json = jsonlib.dumps(topdict)
    return json
