build: set version to 3.4.0-SNAPSHOT

Author: javier-godoy

pom.xml

@@ -5,7 +5,7 @@
 
   <groupId>com.flowingcode.vaadin.addons.demo</groupId>
   <artifactId>commons-demo</artifactId>
-  <version>4.0.0-SNAPSHOT</version>
+  <version>3.4.0-SNAPSHOT</version>
 
   <name>Commons Demo</name>