update version in readme

Author: GaryWilber

README.md

@@ -16,7 +16,7 @@ I am looking for *your* help to make this project even better! If you're interes
 
 The `node-rdkafka` library is a high-performance NodeJS client for [Apache Kafka](http://kafka.apache.org/) that wraps the native  [librdkafka](https://github.com/edenhill/librdkafka) library.  All the complexity of balancing writes across partitions and managing (possibly ever-changing) brokers should be encapsulated in the library.
 
-__This library currently uses `librdkafka` version `1.8.2`.__
+__This library currently uses `librdkafka` version `1.9.0`.__
 
 ## Reference Docs
 
@@ -59,7 +59,7 @@ Using Alpine Linux? Check out the [docs](https://github.com/Blizzard/node-rdkafk
 
 ### Windows
 
-Windows build **is not** compiled from `librdkafka` source but it is rather linked against the appropriate version of [NuGet librdkafka.redist](https://www.nuget.org/packages/librdkafka.redist/) static binary that gets downloaded from `https://globalcdn.nuget.org/packages/librdkafka.redist.1.8.2.nupkg` during installation. This download link can be changed using the environment variable `NODE_RDKAFKA_NUGET_BASE_URL` that defaults to `https://globalcdn.nuget.org/packages/` when it's no set.
+Windows build **is not** compiled from `librdkafka` source but it is rather linked against the appropriate version of [NuGet librdkafka.redist](https://www.nuget.org/packages/librdkafka.redist/) static binary that gets downloaded from `https://globalcdn.nuget.org/packages/librdkafka.redist.1.9.0.nupkg` during installation. This download link can be changed using the environment variable `NODE_RDKAFKA_NUGET_BASE_URL` that defaults to `https://globalcdn.nuget.org/packages/` when it's no set.
 
 Requirements:
  * [node-gyp for Windows](https://github.com/nodejs/node-gyp#on-windows)  (the easies way to get it: `npm install --global --production windows-build-tools`, if your node version is 6.x or below, pleasse use `npm install --global --production [email protected]`)
@@ -96,7 +96,7 @@ var Kafka = require('node-rdkafka');
 
 ## Configuration
 
-You can pass many configuration options to `librdkafka`.  A full list can be found in `librdkafka`'s [Configuration.md](https://github.com/edenhill/librdkafka/blob/v1.8.2/CONFIGURATION.md)
+You can pass many configuration options to `librdkafka`.  A full list can be found in `librdkafka`'s [Configuration.md](https://github.com/edenhill/librdkafka/blob/v1.9.0/CONFIGURATION.md)
 
 Configuration keys that have the suffix `_cb` are designated as callbacks. Some
 of these keys are informational and you can choose to opt-in (for example, `dr_cb`). Others are callbacks designed to
@@ -131,7 +131,7 @@ You can also get the version of `librdkafka`
 const Kafka = require('node-rdkafka');
 console.log(Kafka.librdkafkaVersion);
 
-// #=> 1.8.2
+// #=> 1.9.0
 ```
 
 ## Sending Messages
@@ -144,7 +144,7 @@ var producer = new Kafka.Producer({
 });
 ```
 
-A `Producer` requires only `metadata.broker.list` (the Kafka brokers) to be created.  The values in this list are separated by commas.  For other configuration options, see the [Configuration.md](https://github.com/edenhill/librdkafka/blob/v1.8.2/CONFIGURATION.md) file described previously.
+A `Producer` requires only `metadata.broker.list` (the Kafka brokers) to be created.  The values in this list are separated by commas.  For other configuration options, see the [Configuration.md](https://github.com/edenhill/librdkafka/blob/v1.9.0/CONFIGURATION.md) file described previously.
 
 The following example illustrates a list with several `librdkafka` options set.