code: function updateDomainDns (dns, ip, cb) {
          var body = {
              content: ip
          };
          _hoverRequest('PUT', '/dns/' + dns, body, cb);
      }
docs: Update an existing domain record
  
  @param {String} dns DNS identifier
  @param {String} ip New IP Address of record
  @param {Function} cb
  @api public