bump version to 2.3.18

Author: SidneyAllen

README.md

@@ -1,6 +1,6 @@
 # Xero-Java
 
-[![Maven Central](https://img.shields.io/badge/Maven%20Central-2.3.17-green.svg)](https://search.maven.org/artifact/com.github.xeroapi/xero-java/2.3.17/jar)
+[![Maven Central](https://img.shields.io/badge/Maven%20Central-2.3.18-green.svg)](https://search.maven.org/artifact/com.github.xeroapi/xero-java/2.3.18/jar)
 
 This is the official Java SDK for Xero's API. It supports accounting, fixed asset and bank feed API endpoints. All third party libraries dependencies managed with Maven.
 
@@ -219,7 +219,7 @@ try (FileInputStream privateKeyStream = new FileInputStream(config.getPathToPriv
 ```
 
 ## Logging
-The SDK uses log4j2.  To configure, add a log4j.properties file to the Resources directory.
+The SDK uses [SLF4J](http://www.slf4j.org/index.html) that allows you to plug in the logging library of your choice at deployment time.  This[blog post explains how to add log4j2](https://www.baeldung.com/slf4j-with-log4j2-logback) for logging.  To configure, add a log4j.properties file to the Resources directory.
 
 
 ## How to use the Xero-Java SDK
@@ -658,7 +658,6 @@ Example config.json with optional keystore attributes
 ```
 
 
-
 ## Acknowledgement
 
 Special thanks to [Connectifier](https://github.com/connectifier) and [Ben Mccann](https://github.com/benmccann).  Marshalling and Unmarshalling in XeroClient was derived and extended from [Xero-Java-Client](https://github.com/connectifier/xero-java-client)

pom.xml

@@ -4,7 +4,7 @@
 	<groupId>com.github.xeroapi</groupId>
 	<artifactId>xero-java</artifactId>
 	<packaging>jar</packaging>
-	<version>2.3.17</version>
+	<version>2.3.18</version>
 	<name>Xero-Java SDK</name>
 	<description>This is the official Java SDK for Xero API</description>
 	<url>https://github.com/XeroAPI/Xero-Java</url>

src/main/java/com/xero/api/JsonConfig.java

@@ -15,7 +15,7 @@
 
 public class JsonConfig implements Config {
 
-	private String SDK_VERSION = "2.3.17";
+	private String SDK_VERSION = "2.3.18";
   private String APP_TYPE = "Public";
   private String USER_AGENT = "Xero-Java-SDK";
   private String ACCEPT = "application/xml";