Bumping version to 2.4-SNAPSHOT

Change-Id: I1f30b30740d85a44516f5a6993c17d35f83b6ec3
diff --git a/pom.xml b/pom.xml
index 6f57393..598d3ea 100644
--- a/pom.xml
+++ b/pom.xml
@@ -25,7 +25,7 @@
     </parent>
 
     <artifactId>onos-yang-tools</artifactId>
-    <version>2.3.1</version>
+    <version>2.4-SNAPSHOT</version>
     <packaging>pom</packaging>
 
     <properties>