upgrade to version 2.1.31-SNAPSHOT after release

Author: stevehu

pom.xml

@@ -4,7 +4,7 @@
     <artifactId>light-scheduler</artifactId>
     <packaging>jar</packaging>
     <name>light-scheduler</name>
-    <version>2.1.30</version>
+    <version>2.1.31-SNAPSHOT</version>
     <description>Light Scheduler</description>
     <url>https://github.com/networknt/light-scheduler</url>
 
@@ -102,7 +102,7 @@
         <java.version>11</java.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.main.class>com.networknt.server.Server</project.main.class>
-        <version.light-4j>2.1.30</version.light-4j>
+        <version.light-4j>2.1.31-SNAPSHOT</version.light-4j>
         <version.jackson>2.15.3</version.jackson>
         <version.slf4j>2.0.7</version.slf4j>
         <version.jose4j>0.9.3</version.jose4j>