spray-servlet: Issues when war is deployed to tomcat7

Question

I have created a sample application based on akka and spray-servlet. The code and other details can be found at https://github.com/rajvaibhav/spray-tomcat-routing. I am using embedded tomcat for development purpose. The application runs as expected when I deploy it on the embedded tomcat. But when I deploy successfully the same war file to a stand alone tomcat7 server, I am getting 404 after hitting the application's URL. This is very strange. I have checked my tomcat7 server by deploying another Servlet 3.0 application. That works fine, but following the same steps I am not able to hit my application on standalone tomcat7. Any help appreciated.