upgrade to version 2.3.1 before release in master branch

Author: stevehu

pom.xml

@@ -2,7 +2,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.networknt</groupId>
     <artifactId>lambda-native</artifactId>
-    <version>2.3.1-SNAPSHOT</version>
+    <version>2.3.1</version>
     <packaging>jar</packaging>
     <name>lambda-native</name>
     <description>A middleware Lambda function that handles all the cross-cutting concerns for the downstream Lambda function.</description>
@@ -80,7 +80,7 @@
         <maven.compiler.source>${java.version}</maven.compiler.source>
         <maven.compiler.target>${java.version}</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <version.light-4j>2.3.1-SNAPSHOT</version.light-4j>
+        <version.light-4j>2.3.1</version.light-4j>
         <version.http-client>1.0.14</version.http-client>
         <version.json-schema-validator>1.5.1</version.json-schema-validator>
         <version.jackson>2.18.3</version.jackson>