updated to use vertx-maven-plugin

[kameshsampath]

the following are the changes to this PR

• stack update to 3.4.1 ( instead of 3.4.0-SNAPSHOT) as the maven build was unable to find the vertx stack with version 3.4.0-SNAPSHOT
• Code API fixes to make the application compile with 3.4.1
• added fabric8 vertx-maven-plugin
• removed manual vertx-eventbus.js copying as the fabric8 vertx-maven-plugin with do that automatically during build/run/start
• README update on running the application using fabric8 vertx-maven-plugin

[kameshsampath]

sending new PR after resolving conflicts