feat(sentinel): allow connection to IPv6-only sentinels (#463)

Author: tempname11

lib/connectors/sentinel_connector.js

@@ -226,6 +226,7 @@ SentinelConnector.prototype.resolve = function (endpoint, callback) {
   var client = new Redis({
     port: endpoint.port || 26379,
     host: endpoint.host,
+    family: endpoint.family || this.options.family,
     retryStrategy: null,
     enableReadyCheck: false,
     connectTimeout: this.options.connectTimeout,