set correct link to Cloudwatch limits docs (#111)

README.md

@@ -117,7 +117,7 @@ This is the list of options you could pass as argument to `winston.add`:
  * jsonMessage - `boolean`, format the message as JSON
  * messageFormatter - `function`, format the message the way you like. This function will receive a `log` object that has the following properties: `level`, `msg`, and `meta`, which are passed by winston to the `log` function (see [CustomLogger.prototype.log as an example](https://github.com/winstonjs/winston#adding-custom-transports))
  * proxyServer - `String`, use `proxyServer` as proxy in httpOptions
- * uploadRate - `Number`, how often logs have to be sent to AWS. Be careful of not hitting [AWS CloudWatch Logs limits](http://docs.aws.amazon.com/AmazonCloudWatch/latest/DeveloperGuide/cloudwatch_limits.html), the default is 2000ms.
+ * uploadRate - `Number`, how often logs have to be sent to AWS. Be careful of not hitting [AWS CloudWatch Logs limits](https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/cloudwatch_limits_cwl.html), the default is 2000ms.
  * errorHandler - `function`, invoked with an error object, if not provided the error is sent to `console.error`
  * retentionInDays - `Number`, defaults to `0`, if set to one of the possible values `1, 3, 5, 7, 14, 30, 60, 90, 120, 150, 180, 365, 400, 545, 731, 1827, and 3653` the retention policy on the log group written will be set to the value provided.