code: function createARecord (domain, subdomain, ip, cb) {
          var body = {
              name: subdomain,
              type: 'A',
              content: ip
          };
          _hoverRequest('POST', '/domains/' + domain + '/dns', body, cb);
      }
docs: Create a new A record under the specified domain
  
  @param {String} domain Domain identifier
  @param {String} subdomain Subdomain of record
  @param {String} ip IP Address of record
  @param {Function} cb
  @api public