Servlet 3.1 allows to have web apps with no web.xml but Maven was giving me errors when trying to package the application.
I had to add this to my pom.xml:
<plugin>
<artifactId>maven-war-plugin</artifactId>
<version>2.6</version>
<configuration>
<failOnMissingWebXml>false</failOnMissingWebXml>
</configuration>
</plugin>
