bumping version to 0.4.0-SNAPSHOT

Change-Id: I1bf63ecb85679534a1743738c33c1871563aeec5
diff --git a/pom.xml b/pom.xml
index b81952f..ea83b8e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -6,7 +6,7 @@
   </prerequisites>
   <groupId>net.onrc.onos</groupId>
   <artifactId>onos</artifactId>
-  <version>0.3.1</version>
+  <version>0.4.0-SNAPSHOT</version>
   <packaging>jar</packaging>
   <name>ONOS</name>
   <url>http://onlab.us/</url>